Method and apparatus for sending sounding reference signal SRS

ABSTRACT

This application provides a method including: receiving first configuration information of a sounding reference signal (SRS) resource from a network device, where the first configuration information includes a repetition factor of the SRS resource, and the repetition factor of the SRS resource is a quantity N of positions at which the SRS resource is mapped to a same subcarrier and mapped to at least one continuous symbol in one time unit, where N≥1 and is an integer; determining at least one first frequency domain resource to which the SRS resource is mapped in a first time unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/CN2018/115883, filed on Nov. 16, 2018, which claims priority toChinese Patent Application No. 201711149046.X, filed on Nov. 17, 2017.The disclosures of the aforementioned applications are herebyincorporated by reference in their entireties.

TECHNICAL FIELD

Embodiments of this application relate to the communications field, andin particular, to a method and an apparatus for sending a soundingreference signal (SRS).

BACKGROUND

In a long term evolution (LTE) system or an LTE-advanced (LTE-A) system,uplink measurement of a terminal device is implemented by sending asounding reference signal (SRS). A network device obtains uplink channelstate information by measuring the SRS sent by the terminal device.Further, in the LTE system or the LTE-A system, because terminal deviceshave different distances to the network device (for example, a basestation), a terminal device with a long distance to the network devicemay be limited by power. To ensure that the base station receives an SRSwith sufficient signal strength, a narrowband needs to be ensured forthe terminal device to send an SRS. In this case, measurement of a totalsystem bandwidth can be completed only through SRS frequency hopping.

However, in the LTE system or the LTE-A system, frequency hopping isperformed based on a bandwidth configured at a cell level. That is, afrequency hopping manner for the terminal device is determined based ona total SRS measurement bandwidth that is specifically configured for acell, and only inter-slot frequency hopping is supported. In addition,LTE does not support aperiodic SRS measurement.

It can be learned that, an existing communications system does not wellsupport frequency hopping manners, and has relatively poor flexibility.

SUMMARY

This application provides a method for sending a reference signal, tosupport a plurality of frequency hopping manners, thereby improvingfrequency hopping flexibility.

According to a first aspect, this application provides a method forsending a sounding reference signal SRS, and the method includes:receiving, by a terminal device, first configuration information of anSRS resource from a network device, where the first configurationinformation includes a repetition factor of the SRS resource, and therepetition factor of the SRS resource is a quantity N of positions atwhich the SRS resource is mapped to a same subcarrier and mapped to atleast one continuous symbol in one time unit, where N≥1 and is aninteger; determining, by the terminal device based on the firstconfiguration information, at least one first frequency domain resourceto which the SRS resource is mapped in a first time unit; and sending,by the terminal device, an SRS to the network device on the at least onefirst frequency domain resource.

With reference to the first aspect, in some implementations of the firstaspect, the determining, by the terminal device based on the firstconfiguration information, at least one first frequency domain resourceto which the SRS resource is mapped in a first time unit includes:determining, by the terminal device based on the first configurationinformation and second configuration information, at least one secondfrequency domain resource to which the SRS resource is mapped in thefirst time unit, where the second frequency domain resource is a part ofthe first frequency domain resource; and the sending, by the terminaldevice, an SRS to the network device on the at least one first frequencydomain resource includes: sending, by the terminal device, the SRS tothe network device on the at least one second frequency domain resource.

With reference to the first aspect, in some implementations of the firstaspect, the second configuration information is used to indicate an SRSbandwidth parameter and an SRS bandwidth position parameter, the SRSbandwidth parameter is used to determine a bandwidth occupied by thesecond frequency domain position, and the SRS bandwidth positionparameter is used to determine a position of the bandwidth correspondingto the second frequency domain resource in a bandwidth corresponding tothe first frequency domain resource.

With reference to the first aspect, in some implementations of the firstaspect, the bandwidth corresponding to the second frequency domainresource is a bandwidth in an SRS bandwidth set configured by using auser-level configuration parameter C_(SRS).

With reference to the first aspect, in some implementations of the firstaspect, the first configuration information further includes a quantityN_(symb) ^(SRS) of symbols that can be occupied by the SRS resource inone time unit, where N_(symb) ^(SRS) is a positive integer; thedetermining, by the terminal device based on the first configurationinformation, at least one first frequency domain resource to which theSRS resource is mapped in a first time unit includes: determining, bythe terminal device based on the first configuration information andthird configuration information, at least one third frequency domainresource to which the SRS resource is mapped in the first time unit,where the at least one third frequency domain resource is a subset of aset consisting of the at least one first frequency domain resource inone or more time units; and the sending, by the terminal device, an SRSto the network device on the at least one first frequency domainresource includes: sending, by the terminal device, the SRS to thenetwork device on the at least one third frequency domain position.

With reference to the first aspect, in some implementations of the firstaspect, the third configuration information is used to indicate aquantity t_(symbol) ^(SRS) of reference symbols, and the quantity ofreference symbols is used to determine at least one first frequencydomain resource occupied by the SRS resource in the first time unit,where t_(symbol) ^(SRS) is greater than N_(symb) ^(SRS), and t_(symbol)^(SRS) is a positive integer.

With reference to the first aspect, in some implementations of the firstaspect, the third configuration information is used to configure atleast one fourth frequency domain resource, a bandwidth of the fourthfrequency domain resource is greater than a bandwidth of the firstfrequency domain resource, and the fourth frequency domain resourceincludes only one first frequency domain resource.

With reference to the first aspect, in some implementations of the firstaspect, the SRS resource is an aperiodic SRS resource, a total bandwidthto be measured consists of K non-overlapping SRS bandwidths, and thesending, by the terminal device, an SRS to the network device on the atleast one first frequency domain resource includes: if N_(symb) ^(SRS)is less than K·N, sending, by the terminal device, the SRS on each ofthe at least one first frequency domain resource, and skipping sendingthe SRS in a time unit other than the first time unit; or if N_(symb)^(SRS) is greater than K·N, sending, by the terminal device, the SRS onfirst K·N symbols of the SRS resource.

With reference to the first aspect, in some implementations of the firstaspect, a frequency separation between a first frequency domain positionof the bandwidth occupied by the at least one first frequency domainresource and a first frequency domain position of the total bandwidth tobe measured is not greater than a first threshold, and/or a frequencyseparation between a second frequency domain position of the at leastone first frequency domain resource and a second frequency domainposition of the total bandwidth to be measured is not greater than asecond threshold, where the first threshold is determined based on atleast one of the following parameters: K, N_(symb) ^(SRS), N, the totalbandwidth to be measured, and the user-level SRS bandwidth, and/or thesecond threshold is determined based on at least one of the followingparameters: K, N_(symb) ^(SRS), N, the total bandwidth to be measured,and the user-level SRS bandwidth.

Herein, the first frequency domain position of the bandwidth occupied bythe at least one first frequency domain resource may be a frequencydomain position of a subcarrier having a lowest/highest/centralfrequency in the bandwidth occupied by the at least one first frequencydomain resource, or may be another frequency domain position adjacent tothe frequency domain position of the subcarrier corresponding to thelowest, highest, or center frequency. The second frequency domainposition of the bandwidth occupied by the at least one first frequencydomain resource may be a frequency domain position of a subcarriercorresponding to a highest, lowest, or center frequency in the bandwidthoccupied by the at least one first frequency domain resource, or may beanother frequency domain position adjacent to the frequency domainposition of the subcarrier corresponding to the highest, lowest, orcenter frequency.

Similarly, the first frequency domain position of the total bandwidth tobe measured may be a frequency domain position of a subcarriercorresponding to a lowest, highest, or center frequency in the totalbandwidth to be measured, or may be another frequency domain positionadjacent to the frequency domain position of the subcarriercorresponding to the lowest, highest, or center frequency. The secondfrequency domain position of the total bandwidth to be measured may be afrequency domain position of a subcarrier corresponding to a highest,lowest, or center frequency in the total bandwidth to be measured, ormay be another frequency domain position adjacent to the frequencydomain position of the subcarrier corresponding to the highest, lowest,or center frequency.

With reference to the first aspect, in some implementations of the firstaspect, a frequency separation between third frequency domain positionsof two adjacent first frequency domain resources in the at least onefirst frequency domain resource is not greater than a third threshold,and the third threshold is determined based on at least one of thefollowing parameters: K, N_(symb) ^(SRS), N, the total bandwidth to bemeasured, and the user-level SRS bandwidth.

In this embodiment of this application, the third frequency domainposition may be any frequency domain position in the bandwidth occupiedby the first frequency domain resource, for example, a frequency domainposition of a subcarrier corresponding to a lowest frequency, afrequency domain position of a subcarrier corresponding to a highestfrequency, a frequency domain position of a subcarrier corresponding toa center frequency, or a frequency domain position of any subcarrier.The frequency domain position of the subcarrier corresponding to thelowest frequency is used as an example. That is, a frequency separationbetween frequency domain positions of subcarriers corresponding tolowest frequencies on two adjacent first frequency domain resources isnot greater than the third threshold.

With reference to the first aspect, in some implementations of the firstaspect, a starting symbol of the SRS resource in one time unit, thequantity N_(symb) ^(SRS) of symbols occupied by the SRS resource in onetime unit, and the repetition factor of the SRS resource are jointlyencoded.

With reference to the first aspect, in some implementations of the firstaspect, the SRS resource is an aperiodic SRS resource, and the methodfurther includes: if K is not equal to N_(symb) ^(SRS), skippingsending, by the terminal device, the SRS on the SRS resource in thefirst time unit; if K is greater than N_(symb) ^(SRS), skipping sending,by the terminal device, the SRS on the SRS resource in the first timeunit; or if K is less than N_(symb) ^(SRS), skipping sending, by theterminal device, the SRS on the SRS resource in the first time unit.

With reference to the first aspect, in some implementations of the firstaspect, values of the repetition factor of the SRS resource include 1,2, and 4.

With reference to the first aspect, in some implementations of the firstaspect, the first time unit is a slot, a subframe, a mini-slot, or atransmission time interval TTI.

According to a second aspect, this application provides a method forreceiving a sounding reference signal SRS, and the method includes:sending, by a network device, first configuration information of an SRSresource to a terminal device, where the first configuration informationincludes a repetition factor of the SRS resource, and the repetitionfactor of the SRS resource is a quantity N of positions at which the SRSresource is mapped to a same subcarrier and mapped to at least onecontinuous symbol in one time unit, where N≥1 and is an integer; andreceiving, by the network device, an SRS that is sent by the terminaldevice on at least one first frequency domain resource, where the atleast one first frequency domain resource is a frequency domain resourcethat is determined by the terminal device based on the firstconfiguration information and that is used for sending the SRS.

With reference to the second aspect, in some implementations of thesecond aspect, the method further includes: sending, by the networkdevice, second configuration information to the terminal device, so thatthe terminal device determines at least one second frequency domainresource based on the first configuration information and the secondconfiguration information, where the second frequency domain resource isa part of a bandwidth of the first frequency domain resource; and thereceiving, by the network device, an SRS that is sent by the terminaldevice on at least one first frequency domain resource includes:receiving, by the network device, the SRS that is sent by the terminaldevice on the at least one second frequency domain resource.

With reference to the second aspect, in some implementations of thesecond aspect, the second configuration information is used to indicatean SRS bandwidth parameter and an SRS bandwidth position parameter, theSRS bandwidth parameter is used to determine a bandwidth occupied by thesecond frequency domain resource, and the SRS bandwidth positionparameter is used to determine a position of the bandwidth correspondingto the second frequency domain resource in a bandwidth corresponding tothe first frequency domain resource.

With reference to the second aspect, in some implementations of thesecond aspect, the bandwidth corresponding to the second frequencydomain resource is a bandwidth in an SRS bandwidth set configured byusing a user-level configuration parameter C_(SRS).

With reference to the second aspect, in some implementations of thesecond aspect, the first configuration information further includes aquantity N_(symb) ^(SRS) of symbols that can be occupied by the SRSresource in one time unit, where N_(symb) ^(SRS) is a positive integer;the method further includes: sending, by the network device, thirdconfiguration information to the terminal device, so that the terminaldevice determines at least one third frequency domain resource based onthe first configuration information and the third configurationinformation, where the at least one third frequency domain resource is asubset of a set consisting of the at least one first frequency domainresource in one or more time units; and the receiving, by the networkdevice, an SRS that is sent by the terminal device on at least one firstfrequency domain resource includes: receiving, by the network device,the SRS that is sent by the terminal device on the at least one thirdfrequency domain resource.

With reference to the second aspect, in some implementations of thesecond aspect, the third configuration information is used to indicate aquantity t_(symbol) ^(SRS) of reference symbols, and the quantity ofreference symbols is used to determine at least one first frequencydomain resource occupied by the SRS resource in the first time unit,where t_(symbol) ^(SRS) is greater than N_(symb) ^(SRS), and t_(symbol)^(SRS) is a positive integer.

With reference to the second aspect, in some implementations of thesecond aspect, the third configuration information is used to configureat least one fourth frequency domain resource, a bandwidth of the fourthfrequency domain resource is greater than a bandwidth of the firstfrequency domain resource, and the fourth frequency domain resourceincludes only one first frequency domain resource.

With reference to the second aspect, in some implementations of thesecond aspect, the SRS resource is an aperiodic SRS resource, a totalbandwidth to be measured corresponds to K non-overlapping frequencyresources, and bandwidths of the frequency resources are SRS bandwidths,and the receiving, by the network device, an SRS that is sent by theterminal device on at least one first frequency domain resourceincludes: if N_(symb) ^(SRS) is less than K·N, sending, by the terminaldevice, the SRS on each of the at least one first frequency domainresource, and skipping sending the SRS in a time unit other than thefirst time unit; or if N_(symb) ^(SRS) is greater than K·N, sending, bythe terminal device, the SRS on first K·N symbols of the SRS resource.

With reference to the second aspect, in some implementations of thesecond aspect, a frequency separation between a lowest first frequencydomain resource in the at least one first frequency domain resource anda lowest frequency of the total bandwidth to be measured is not greaterthan a first threshold, and/or a frequency separation between a highestfrequency domain position in the at least one first frequency domainresource and a highest frequency of the total bandwidth to be measuredis not greater than a second threshold, where the first threshold andthe second threshold are determined based on at least one of thefollowing parameters: K, N_(symb) ^(SRS), N, the total bandwidth to bemeasured, and a user-level SRS bandwidth.

With reference to the second aspect, in some implementations of thesecond aspect, a frequency separation between two adjacent firstfrequency domain resources in the at least one first frequency domainresource is not greater than a third threshold, and the third thresholdis determined based on at least one of the following parameters: K,N_(symb) ^(SRS), N, the total bandwidth to be measured, and theuser-level SRS bandwidth.

With reference to the second aspect, in some implementations of thesecond aspect, a starting symbol of the SRS resource in one time unit,the quantity N_(symb) ^(SRS) of symbols occupied by the SRS resource inone time unit, and the repetition factor of the SRS resource are jointlyencoded.

With reference to the second aspect, in some implementations of thesecond aspect, the SRS resource is an aperiodic SRS resource, and themethod further includes: if K is not equal to N_(symb) ^(SRS), failingto receive, by the network device, the SRS in the first time unit; if Kis greater than N_(symb) ^(SRS), failing to receive, by the networkdevice, the SRS in the first time unit; or if K is less than N_(symb)^(SRS), failing to receive, by the network device, the SRS in the firsttime unit.

With reference to the second aspect, in some implementations of thesecond aspect, values of the repetition factor of the SRS resourceinclude 1, 2, and 4.

With reference to the second aspect, in some implementations of thesecond aspect, the first time unit is a slot, a subframe, a mini-slot,or a transmission time interval TTI.

According to a third aspect, this application provides a terminaldevice, and the terminal device has functions for implementing theterminal device in the method designs according to the first aspect. Thefunctions may be implemented by hardware, or may be implemented byhardware executing corresponding software. The hardware or the softwareincludes one or more units corresponding to the foregoing functions.

According to a fourth aspect, this application provides a networkdevice, and the network device has functions for implementing thenetwork device in the method designs according to the second aspect. Thefunctions may be implemented by hardware, or may be implemented byhardware executing corresponding software. The hardware or the softwareincludes one or more units corresponding to the foregoing functions.

According to a fifth aspect, this application provides a terminaldevice, and the terminal device includes a transceiver, a processor, anda memory. The processor is configured to control the transceiver toreceive and send a signal, the memory is configured to store a computerprogram, and the processor is configured to invoke the computer programfrom the memory and run the computer program, so that the terminaldevice performs the method in the first aspect.

According to a sixth aspect, this application provides a network device,and the network device includes a transceiver, a processor, and amemory. The processor is configured to control the transceiver toreceive and send a signal, the memory is configured to store a computerprogram, and the processor is configured to invoke the computer programfrom the memory and run the computer program, so that the network deviceperforms the method in the second aspect.

According to a seventh aspect, this application provides acommunications apparatus, and the communications apparatus may be theterminal device in the foregoing method designs, or a chip disposed inthe terminal device. The communications apparatus includes: a memoryconfigured to store computer-executable program code, a communicationsinterface, and a processor, where the processor is coupled to the memoryand the communications interface. The program code stored in the memoryincludes an instruction, and when the processor executes theinstruction, the communications apparatus is enabled to perform themethod performed by the terminal device in any possible design of thefirst aspect or the second aspect.

According to an eighth aspect, this application provides acommunications apparatus, and the communications apparatus may be thenetwork device in the foregoing method designs, or a chip disposed inthe network device. The communications apparatus includes: a memory,configured to store computer-executable program code, a communicationsinterface, and a processor, where the processor is coupled to the memoryand the communications interface. The program code stored in the memoryincludes an instruction, and when the processor executes theinstruction, the communications apparatus is enabled to perform themethod performed by the network device in any possible design of thefirst aspect or the second aspect.

According to a ninth aspect, this application provides a computerprogram product. The computer program product includes: computer programcode. When the computer program code is run on a computer, the computeris enabled to perform the method in each of the foregoing aspects.

According to a tenth aspect, a computer-readable medium is provided. Thecomputer-readable medium stores program code. When the computer programcode is run on a computer, the computer is enabled to perform the methodin each of the foregoing aspects.

According to an eleventh aspect, this application provides a chipsystem. The chip system includes a processor, configured for a terminaldevice to implement a function in the foregoing aspects, for example,receiving or processing data and/or information in the foregoingmethods. In a possible design, the chip system further includes amemory. The memory is configured to store a program instruction and datanecessary to the terminal device. The chip system may include a chip, ormay include a chip and another discrete device.

According to a twelfth aspect, this application provides a chip system.The chip system includes a processor, configured to support a networkdevice in implementing a function in the foregoing aspects, for example,sending or processing data and/or information in the foregoing methods.In a possible design, the chip system further includes a memory. Thememory is configured to store a program instruction and data necessaryto the network device. The chip system may include a chip, or mayinclude a chip and another discrete device.

In the embodiments of this application, the network device can support aplurality of frequency hopping manners by configuring the repetitionfactor of the SRS resource. For example, the network device can supportinter-slot frequency hopping, inter-slot frequency hopping and frequencyhopping on each symbol in a slot, inter-slot frequency hopping andfrequency hopping on every two symbols in a slot, and frequency hoppingof a periodic or semi-persistent SRS resource and frequency hopping ofan aperiodic SRS. This can improve frequency hopping flexibility.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a wireless communications system 100 to which embodimentsof this application are applicable;

FIG. 2 a schematic interaction diagram of sending a reference signalaccording to an embodiment of this application;

FIG. 3 is a schematic diagram of a repetition factor of an SRS resource;

FIG. 4 is a schematic diagram of postponing sending an SRS by a terminaldevice;

FIG. 5 is a schematic diagram of determining a second frequency domainresource according to an embodiment of this application;

FIG. 6 is a schematic diagram of determining a third frequency domainresource according to an embodiment of this application;

FIG. 7 is a schematic diagram of sending an SRS by a terminal device;

FIG. 8 is another schematic diagram of sending an SRS by a terminaldevice;

FIG. 9 shows a frequency hopping pattern based on a configurationaccording to an embodiment of this application;

FIG. 10 shows a frequency hopping pattern based on another configurationaccording to an embodiment of this application;

FIG. 11 shows a frequency hopping pattern based on a configuration;

FIG. 12 shows a frequency hopping pattern based on anotherconfiguration;

FIG. 13 shows a frequency hopping pattern based on a configurationaccording to an embodiment of this application;

FIG. 14 shows a frequency hopping pattern based on another configurationaccording to an embodiment of this application;

FIG. 15 shows a frequency hopping pattern based on a configurationaccording to an embodiment of this application;

FIG. 16 shows a frequency hopping pattern based on another configurationaccording to an embodiment of this application;

FIG. 17 is a schematic block diagram of a terminal device 500 accordingto an embodiment of this application;

FIG. 18 is a schematic block diagram of a network device 600 accordingto an embodiment of this application;

FIG. 19 is a schematic structural diagram of a terminal device 700according to an embodiment of this application; and

FIG. 20 is a schematic structural diagram of a network device 800according to an embodiment of this application.

DESCRIPTION OF EMBODIMENTS

The following describes technical solutions of this application withreference to accompanying drawings.

FIG. 1 shows a wireless communications system 100 to which embodimentsof this application are applicable. The communications system 100 mayinclude at least one network device 101. The network device 101communicates with one or more terminal devices (for example, a terminaldevice 102 and a terminal device 103 shown in FIG. 1). The networkdevice 101 may be a base station, a device obtained after a base stationis integrated with a base station controller, or another device having asimilar communication function.

The wireless communications system described in the embodiments of thisapplication may include but is not limited to: a global system formobile communications (GSM) system, a code division multiple access(CDMA) system, a wideband code division multiple access (WCDMA) system,a general packet radio service (GPRS), a long term evolution (LTE)system, a long term evolution advanced (LTE-A) system, an LTE frequencydivision duplex (FDD) system, LTE time division duplex (TDD), auniversal mobile telecommunications system (UMTS), a worldwideinteroperability for microwave access (WiMAX) communications system, anext-generation communications system (for example, fifth-generation(5G) communications system), a system converged by a plurality of accesssystems, an evolved system, three application scenarios of anext-generation 5G mobile communications system: eMBB, URLLC, and eMTC,or a future emerged new communications system.

The network device 101 in the embodiments of this application may be anydevice having a wireless receiving and sending function or a chip thatcan be disposed in the device. The device includes but is not limitedto: a base station (for example, a NodeB or an evolved NodeB (eNodeB)),a network device in a fifth-generation (5G) communications system (forexample, a transmission point (TP), a transmission reception point(TRP), a base station, or a small cell device), a network device in afuture communications system, and an access node, a wireless relay node,a wireless backhaul node, and the like in a wireless fidelity (Wi-Fi)system.

The terminal device (for example, the terminal device 102 in FIG. 1) inthe embodiments of this application may include various access terminalshaving a wireless communication function, a subscriber unit, asubscriber station, a mobile station, a mobile console, a remotestation, a remote terminal, a mobile device, a user terminal, aterminal, a wireless communications device, a user agent, or a userapparatus. For example, the terminal device may be a mobile phone, atablet computer (Pad), a computer having a wireless sending andreceiving function, a virtual reality (VR) terminal device, an augmentedreality (AR) terminal device, a wireless terminal in industrial control,a machine type communication (MTC) terminal, customer premise equipment(CPE), a wireless terminal in self driving, a wireless terminal inremote medicine, a wireless terminal in a smart grid, a wirelessterminal in transportation safety, a wireless terminal in a smart city,a wireless terminal in a smart home, and the like. An applicationscenario is not limited in the embodiments of this application. In thisapplication, the foregoing terminal device and the chip that can bedisposed in the foregoing terminal device are collectively referred toas a terminal device.

For ease of understanding the solutions, some concepts in theembodiments of this application are briefly described first.

An SRS resource is a resource that is configured by the network devicefor the terminal device and that is used for sending a soundingreference signal (SRS). In the embodiments of this application, theterminal device sends an SRS to the network device on a per time unitbasis. The SRS resource configured by the network device for theterminal device includes configurations of a frequency domain resource,a time domain resource, a code domain resource, and the like. Theembodiments of this application are mainly about the configurations ofthe time domain resource and the frequency domain resource. Optionally,the SRS resource may be understood as an SRS resource configuration.

A time unit described in the embodiments of this application may be asubframe, a slot, a mini-slot, or a transmission time interval (TTI),and a first time unit is used as an example of a time unit.Alternatively, the first time unit may be understood as a time unit inwhich an SRS needs to be transmitted currently.

A total bandwidth to be measured represents a frequency hopping range,and is one element in a bandwidth set configured by using a user-levelconfiguration parameter C_(SRS), and denoted as b_(hop) in thisapplication.

In addition, that “the total bandwidth to be measured includes Knon-overlapping frequency resources” and “a total quantity K of hops”described in the embodiments of this application actually describe thetotal bandwidth to be measured from different perspectives. In otherwords, the total bandwidth to be measured can be covered in measurementonly after frequency hopping of K hops is performed. Each hopcorresponds to a bandwidth occupied by one of the K non-overlappingfrequency resources. In addition, a bandwidth occupied by each of the Knon-overlapping frequency resources is an SRS bandwidth.

The user-level configuration parameter C_(SRS) is used to configure thebandwidth set, where the bandwidth set includes a plurality of SRSbandwidths.

A user-level configuration bandwidth B_(SRS) is an SRS bandwidth in thebandwidth set configured by using C_(SRS).

The SRS bandwidth is a bandwidth used to transmit an SRS in a symbol.

For meanings of these parameters, refer to a related description in LTE.It should be noted that, in LTE, C_(SRS) is a cell-level configurationparameter, whereas in NR, C_(SRS) is a user-level configurationparameter.

In addition, two concepts easy to be mixed in the embodiments of thisapplication are briefly distinguished. One is a quantity N_(symb) ^(SRS)of symbols that can be occupied by the SRS resource in a time. The otheris a quantity of symbols in which the terminal device sends an SRS tothe network device in a time unit. The former one may be considered as aconfiguration of the network device. The terminal device can send theSRS by using the configuration of the network device. In this case, thequantity of symbols used by the terminal device for sending the SRS isequal to N_(symb) ^(SRS). Alternatively, the terminal device may sendthe SRS by using a part of the SRS resource (for example, a part offrequency domain resource or a part of time domain resource) configuredby the network device. In this case, the quantity of symbols used by theterminal device for sending the SRS is not equal to N_(symb) ^(SRS), andmay be, for example, less than N_(symb) ^(SRS).

In addition, numbers “first”, “second”, and the like that appear in theembodiments of this application are merely used for distinguishingbetween different described objects, for example, for distinguishingbetween different frequency domain resources (for example, a firstfrequency domain resource and a second frequency domain resource), athreshold (for example, a first threshold, a second threshold, and athird threshold), or configuration information, and should notconstitute a limitation on the technical solutions in the embodiments ofthis application.

FIG. 2 a schematic interaction diagram of sending a reference signalaccording to an embodiment of this application.

This specification describes the technical solutions in the embodimentsof this application by using a sounding reference signal (SRS) as anexample. The technical solutions in this application may be furtherapplied to scenarios of transmission of other reference signals forchannel measurement.

210. A network device sends first configuration information of an SRSresource to a terminal device. The terminal device receives the firstconfiguration information of the SRS resource from the network device.

The first configuration information of the SRS resource is used toindicate time domain parameters configured by the network device for theSRS resource. Specifically, these time domain parameters include aslot-level time domain parameter and a symbol-level time domainparameter.

For a periodic or semi-persistent SRS resource, the slot-level timedomain parameter includes a period and a time domain offset of the SRSresource.

For an aperiodic SRS resource, the slot-level time domain parameterincludes a time domain offset of the SRS resource, or a minimum value ofthe time domain offset.

NR supports different subcarrier spacings and a relatively large carrierrange. In addition, channel changing speeds are different at differentcarrier frequencies. For example, a channel changes quickly at a highfrequency, and changes slowly at a low frequency. In addition, differentsubcarrier spacings correspond to different slot lengths. Therefore,considering all these factors, a same slot-level period corresponds todifferent absolute time lengths. For example, a time length of a 15 kHzslot may be four times a time length of a 60 kHz slot.

To consider measurement requirements of the terminal device on both thecarrier frequency and the subcarrier spacing, this embodiment of thisapplication provides the following three configuration solutions(denoted as Solution A, Solution B, and Solution C below).

Solution A

A relatively large period-configurable range is supported.

In Solution A, the network device may configure a slot-level parameterof an SRS resource based on Table 1. Compared with a configuration inLTE in which only a period ranging from 2 ms to 320 ms is supported, aconfiguration of 640 slots and 1280 slots is added. The network devicecan configure a relatively large slot-level period for a relativelylarge subcarrier spacing.

TABLE 1 SRS slot configuration Slot-level period Slot offset index(I_(SRS)) T_(SRS) T_(offset) 0-4 5 I_(SRS)  5-14 10 I_(SRS) − 5  15-3420 I_(SRS) − 15  35-74 40 I_(SRS) − 35   75-154 80 I_(SRS) − 75  155-314160 I_(SRS) − 155 315-634 320 I_(SRS) − 315  635-1274 640 I_(SRS) − 6351275-2554 1280  I_(SRS) − 1275 2555-4095 reserved reserved

Alternatively, referring to Table 2, a case in which the period is 2 maynot be included.

TABLE 2 SRS slot configuration Slot-level period Slot Offset index(I_(SRS)) T_(SRS) T_(offset) 2-6 5 I_(SRS) − 2   7-16 10 I_(SRS) − 7 17-36 20 I_(SRS) − 17  37-76 40 I_(SRS) − 37   77-156 80 I_(SRS) − 77 157-316 160 I_(SRS) − 157 317-636 320 I_(SRS) − 317  637-1276 640I_(SRS) − 637 1277-2556 1280  I_(SRS) − 1277 2557-4095 reserved reserved

Alternatively, referring to Table 3, some periods includes a pluralityof time offsets. Empty parts in Table 3 are not limited.

TABLE 3 SRS slot configuration Slot-level period Slot offset index(I_(SRS)) T_(SRS) T_(offset) 0 5 {0, 1} 1 5 {0, 2} 2 5 {0, 3} 3 5 {0, 4}4 5 {1, 2} 5 5 {1, 3} 6 5 {1, 4} 7 5 {2, 3} 8 5 {2, 4} 9 5 {3, 4} 5 1020 40 80 160 320 640 1280 reserved

Solution B

Different subcarrier spacings correspond to different configurationtables, or a group of subcarrier spacings correspond to a group ofconfiguration tables.

For example, referring to Table 4 and Table 5, 15 kHz corresponds to aperiod of 2 to 320 slots, and 60 kHz corresponds to a period of 10 to1280 slots.

TABLE 4 SRS slot configuration Slot-level period Slot offset index 15kHz 15 kHz 15 kHz (relatively long slot) T_(SRS) (slot) T_(offset) 0-1 2I_(SRS) 2-6 5 I_(SRS) − 2   7-16 10 I_(SRS) − 7  17-36 20 I_(SRS) − 1737-76 40 I_(SRS) − 37  77-156 80 I_(SRS) − 77 157-316 160  I_(SRS) − 157317-636 320  I_(SRS) − 317 636-639 reserved reserved

TABLE 5 SRS slot configuration Slot-level period Slot offset index 60kHz 60 kHz 60 kHz (relatively short slot) I_(SRS) (slot) T_(offset) 0-910 I_(SRS) 10-29 20 I_(SRS) − 10  30-69 40 I_(SRS) − 30   70-149 80I_(SRS) − 70  150-309 160 I_(SRS) − 150 310-629 320 I_(SRS) − 310 630-1269 640 I_(SRS) − 630 1270-2549 1280  I_(SRS) − 1270 2550-4095reserved reserved

Alternatively, the case in which the period is 2 may not be included, orone period includes a plurality of offsets.

Solution C

Different carrier frequencies correspond to different configurationtables. For example, Table 4 and Table 5 in Solution B respectivelycorrespond to carrier frequencies above 6 GHz and below 6 GHz.Alternatively, different carrier frequencies correspond to differentperiod units. For example, in the tables in Solution A and Solution B, aslot is used as a unit of the period. However, in Solution C, a periodunit corresponding to a carrier frequency below 6 GHz is k=2^(μ) slots,and a period unit corresponding to a carrier frequency above 6 GHz isk=2^(μ−2) slots. Referring to Table 6, μ is an index of a subcarrierspacing.

TABLE 6 Subcarrier spacing μ Δf = 2^(μ) · 15 [kHz] 0 15 1 30 2 60 3 1204 240 5 480

Alternatively, the case in which the period is 2 may not be included, orone period includes a plurality of offsets.

In addition, for an aperiodic SRS resource, the network device mayconfigure or predefine a time interval between a PDCCH or a controlresource set (CORESET) carrying DCI and the SRS resource, or a minimumvalue of the time interval.

For ease of description, a slot in which the PDCCH or the CORESETcarrying the DCI is located is denoted as a slot m, and a slot in whichthe SRS resource is located is denoted as a slot n, where m≤n, and bothm and n are positive integers.

Specifically, the period may be measured in units defined in optionalcases listed below.

(1) A slot-level interval between the slot m and the slot n.

(2) A symbol-level interval between a symbol in which the PDCCH or theCORESET carrying the DCI is located and the first or the last symbol ofthe SRS resource in the slot n.

For the case (2), optionally, a starting symbol of the SRS resource doesnot need to be configured.

Optionally, optional values of the symbol-level interval fall within aparticular range, ensuring that the SRS resource is mapped to symbolsthat can be used for sending an SRS, for example, the last six symbolsof the slot n.

(3) A time interval is configured by the network device, and the timeinterval has a minimum value, where the minimum value may be predefined.For example, the minimum value may be predefined as four slots.Alternatively, the minimum value may be reported by the terminal deviceto the network device based on a measurement capability of the terminaldevice. Optionally, the network device may select a time interval fromsome candidate values and configure the time interval for the terminaldevice.

(4) The terminal device may report at least one of the following: a timeinterval, a minimum value of a time interval, and a candidate value of atime interval.

(5) The network device configures the time interval for the SRSresource.

Optionally, the network device configures a time interval for an SRSresource set including the SRS resource. When sending an SRS resource inan SRS resource set, the terminal device uses the time interval of theSRS resource set. In this case, optionally, the network device may notneed to configure time interval information for each SRS resource in theSRS resource set. Alternatively, the terminal device determines a timeinterval between transmission of the DCI and transmission of the SRSresource based on both the time interval of the SRS resource set and thetime interval of the SRS resource (for example, adding the two). Thetime interval of the SRS resource set and/or the time interval of theSRS resource may be determined based on an identifier of the SRSresource set or an identifier of the SRS resource. For example, the timeinterval is equal to an identifier value or a sum of an identifier valueand an offset value.

The terminal device determines a time domain resource of the SRSresource based on the symbol or the slot in which the PDCCH or theCORESET carrying the DCI is located and the time interval. For example,the terminal device determines that m is a sum of n and the time domaininterval. For another example, the terminal device determines a timedomain resource of the SRS resource based on a sum of the symbol inwhich the PDCCH or the CORESET carrying the DCI is located and the timedomain interval.

Optionally, the DCI may be used to trigger at least one SRS resource, ormay be used to trigger at least one SRS resource set. When the DCI isused to trigger the SRS resource set, the DCI includes identificationinformation used to indicate the SRS resource set or an identifier usedto indicate the SRS resource set.

Optionally, the foregoing method for determining a time domain intervalfor an aperiodic SRS may be further applied to a semi-persistent SRS.

The semi-persistent SRS means that DCI or a MAC CE may be used totrigger to activate transmission of an SRS, and DCI or a MAC CE may beused to trigger to deactivate the transmission of the SRS.Alternatively, DCI or a MAC CE may be used to trigger to activatetransmission of an SRS, and the transmission of the SRS is deactivatedafter a period of time. The period of time may be specified in aprotocol (and does not need to be configured by the base station,locally prestored, or preconfigured) or configured by the base station.Alternatively, activation may be performed after a period of time afterthe configuration information is received, and DCI or a MAC CE is usedto trigger deactivation, or deactivation is performed after a period oftime. The period of time from receiving the configuration information toperforming the activation may be specified in the protocol (and does notneed to be configured by the base station, locally prestored, orpreconfigured) or configured by the base station. The period of timefrom the activation to the deactivation may also be specified in theprotocol (and does not need to be configured by the base station,locally prestored, or preconfigured) or configured by the base station.

Similar to the method for determining a time domain interval for anaperiodic SRS, the base station configures or predefines a first timeinterval and/or a second time interval. The first time interval is atime interval or a minimum value of the time interval between a PDCCH ora CORESET in which DCI activating a semi-persistent SRS resource islocated or a PDSCH in which a MAC CE activating a semi-persistent SRSresource is located and the semi-persistent SRS resource. For example,the terminal device may start to perform transmission at a firsttransmission opportunity of the semi-persistent SRS after the timeinterval, where the transmission opportunity is determined based on timedomain configuration information of the semi-persistent SRS. The secondtime interval is a time interval between a PDCCH or a CORESET in whichDCI deactivating the semi-persistent SRS resource is located or a PDSCHin which a MAC CE deactivating the semi-persistent SRS resource islocated and a time point at which transmission of the semi-persistentSRS resource is stopped or the SRS resource is transmitted for the lasttime. For example, the terminal device may stop transmitting thesemi-persistent SRS after the time interval.

Optionally, specific methods for configuring and reporting a timeinterval are the same as those corresponding to the aperiodic SRSresource.

Optionally, the DCI or the MAC CE may be used to activate or deactivateat least one semi-persistent SRS resource, or may be used to activate ordeactivate at least one semi-persistent SRS resource set. When the DCIor the MAC CE is used to activate or deactivate the semi-persistent SRSresource set, the DCI or the MAC CE includes identification informationused to indicate the semi-persistent SRS resource set, an identifierused to indicate the SRS resource set, or an identifier of thesemi-persistent SRS resource set in all semi-persistent SRS resourcesets or in all SRS resource sets, or the DCI or the MAC CE providessupport in a form of a bitmap. Each bit in the bitmap corresponds to onesemi-persistent SRS resource set. A length of the bitmap is not lessthan a quantity of configured semi-persistent SRS resource sets, orequal to the quantity of semi-persistent SRS resource sets or a maximumquantity of semi-persistent SRS resource sets.

Optionally, some rows or some columns in the tables in the foregoingsolutions may be separately used, or at least some rows or at least somecolumns may be used as a part of a complete configuration table. This isnot limited herein.

Symbol-level time domain parameters of the SRS resource are describedbelow.

In this embodiment of this application, the symbol-level time domainparameters of the SRS resource mainly include the following:

(1) A starting symbol of the SRS resource in a slot.

Because an SRS is usually configured in last M symbols in a slot, astarting symbol of the SRS resource in the slot is in the last M symbolsin the slot. For example, if a starting symbol of the SRS resource in aslot is in the last six symbols of the slot, a position of the startingsymbol of the SRS resource in the slot is the last six symbols.

(2) A quantity of symbols of the SRS resource.

The quantity of symbols of the SRS resource is a quantity (denoted asN_(symb) ^(SRS) below) of symbols occupied by the SRS resource in aslot, where N_(symb) ^(SRS) is a positive integer.

(3) A repetition factor of the SRS resource.

In this embodiment of this application, the repetition factor of the SRSresource is a quantity N of positions at which the SRS resource ismapped to a same subcarrier and mapped to at least one continuous symbolin a slot, where N≥1 and is an integer.

For brevity in description, the repetition factor of the SRS resource isdenoted as L_(r) below, that is, L_(r)=N.

In this embodiment of this application, the repetition factor may alsobe referred to as a repetition length.

FIG. 3 is a schematic diagram of a repetition length of an SRS resource.For example, in FIG. 3, a quantity of symbols of the SRS resource isequal to 4. As shown in (A) in FIG. 3, the repetition length of the SRSresource is equal to 1. As shown in (B) in FIG. 3, the repetition lengthof the SRS resource is equal to 2. As shown in (C) in FIG. 3, therepetition length of the SRS resource is equal to 4.

It may be understood that, the starting symbol of the SRS resource inthe slot, the quantity of symbols of the SRS resource, and therepetition length of the SRS resource meet some constraintrelationships. For example, the starting symbol of the SRS resource inthe slot determines a maximum value of the quantity of symbols of theSRS resource. For example, if a start position of the SRS resource inthe slot is the last symbol in the slot, the quantity of symbols of theSRS resource is only equal to 1. For another example, the quantity ofsymbols of the SRS resource determines the repetition length of the SRSresource. In other words, the repetition length of the SRS resource doesnot exceed the quantity of symbols of the SRS resource.

If a quantity of symbols in a slot is denoted as N, and indexes ofsymbols in the slot is 0 to N−1, where N is a positive integer, theconstraint relationships may be represented as follows:

(1) A maximum value of the starting symbol of the SRS is not greaterthan N−M.

(2) A sum of the quantity of symbols of the SRS resource and thestarting symbol of the SRS resource is not greater than N−1.

Optionally, the quantity of symbols of the SRS resource may be equal to1, 2 or 4.

Optionally, the repetition factor of the SRS resource may be equal to 1,2 or 4.

Further, considering these constraint relationships, this applicationproposes to jointly encode the three symbol-level time domain parametersof the SRS resource, to reduce resource overheads.

It may be understood that, the starting symbol of the SRS resource, thequantity of symbols of the SRS resource, and the repetition factor ofthe SRS resource may be jointly encoded by the network device, and thensent to the terminal device by using a piece of signaling. For example,this signaling may be the first configuration information in thisembodiment of this application. The following describes Table 7 forjoint encoding by using M=6 as an example.

TABLE 7 Symbol Starting Quantity l_(SRS) ^(symbol) Repetition lengthconfiguration of an symbol of symbols of an L_(r) of an SRS SRS resourceD_(SRS) l_(SRS) ^(start) SRS resource resource (symbol) 0-5 13-D_(SRS) 11  6-10 18-D_(SRS) 2 1 11-15 23-D_(SRS) 2 2 16-18 26-D_(SRS) 4 1 19-2129-D_(SRS) 4 2 22-24 32-D_(SRS) 4 4 25-31 reserved reserved reserved

In an optional solution, the repetition length of the SRS resource mayalternatively be separately configured, referring to Table 8 below.

TABLE 8 Symbol Quantity l_(SRS) ^(symbol) configuration of an Startingof symbols of an SRS resource D_(SRS) symbol l_(SRS) ^(start) SRSresource 0-5 13-D_(SRS) 1  6-10 18-D_(SRS) 2 11-13 12-D_(SRS) 4 14-15reserved reserved

In addition, the repetition length of the SRS resource is configured asTable 9.

TABLE 9 Configuration of a repetition Repetition length L_(r) of lengthof an SRS resource an SRS resource 00 1 01 2 10 4 11 reserved

Optionally, some rows or some columns in the tables in the foregoingsolutions may be separately used, or at least some rows or at least somecolumns may be used as a part of a complete configuration table. This isnot limited herein.

220. The terminal device determines, based on time domain configurationinformation of the SRS resource, that the SRS resource is mapped to atleast one first frequency domain position in a first time unit.

For an aperiodic SRS resource, the time domain configuration informationof the SRS resource may be carried in downlink control information(DCI).

If a slot in which the terminal device receives the downlink controlinformation is a slot n, the terminal device may send an SRS to thenetwork device in a slot n+k, where k is a time domain offset of the SRSresource, and n and k are positive integers.

If an SRS cannot be sent in a symbol that is configured in the slot n+kand that is used for sending an SRS, for example, the SRS resource andthe PUCCH or the PUSCH are configured in a same symbol, or a slot formatindicator (SFI) indicates that the SRS resource is a downlink resourceor an unknown resource, the terminal device sends an SRS on a samesymbol position in a slot n+k+1. FIG. 4 is a schematic diagram ofpostponing sending an SRS by a terminal device.

Further, if the SRS still cannot be sent in a symbol that is configuredin the slot n+k+1 and that is used for sending an SRS, the terminaldevice sends the SRS in a slot n+k+2, and so on.

However, to avoid postponing sending the SRS for a plurality of times,the network device may preconfigure a maximum time domain offset t(where t>0 and is an integer) for sending the SRS. That is, an SRS thatis triggered by DCI in the slot n will not be sent in a slot after aslot n+t.

The time domain offset t may be configured by using higher layersignaling and/or DCI of the network device. Alternatively, t may bepredefined.

The following describes the process of determining, by the terminaldevice based on the first configuration information, at least one firstfrequency domain resource to which the SRS resource is mapped in a firsttime unit.

For ease of understanding, the following describes an example in which atime unit is a slot.

Specifically, the terminal device determines, based on the firstconfiguration information of the SRS resource and a current slot, acount n_(SRS) of for SRS sending, and then determines, based on n_(SRS)a frequency domain resource to which the SRS resource is mapped in thecurrent slot (where the frequency domain resource is referred to as afirst frequency domain resource in this application, and a bandwidth ofthe first frequency domain resource is the SRS bandwidth and isconfigured by using B_(SRS)).

The following separately describes a periodic (includingsemi-persistent) SRS resource and an aperiodic SRS resource.

1. Periodic or Semi-Persistent SRS Resource.

For a periodic or semi-persistent SRS resource, n_(SRS) represents acount of positions that can be used for transmitting an SRS on a samesubcarrier in continuous symbols in a radio frame period. n_(SRS) can bedetermined through calculation based on the following parameters: asystem frame number, a slot number, a symbol number (namely, a symbolindex), a starting symbol of the SRS resource, a quantity of symbols ofthe SRS resource, and a repetition factor of the SRS resource.

Specifically, n_(SRS) may be determined through calculation according tothe following formula (1):n _(SRS)=└(N _(symb) ^(SRS)·└(n·N _(frame) ^(slot,μ) +n _(s))/T _(SRS)┘+n _(symbol) −t _(start) ^(SRS))/L _(r)┘  (1)

Physical meanings of the parameters in the formula (1) are as follows:N_(symb) ^(SRS) represents the quantity of symbols of the SRS resource;n represents the system frame number; N_(frame) ^(slot,μ) represents theslot number; n_(s) represents a slot number in a frame; T_(SRS)represents an SRS resource period; n_(symbol) represents a symbol in aslot; l_(start) ^(SRS) represents the starting symbol of the SRSresource in a slot (the starting symbol of the SRS resource for shortbelow); L_(r) represents the repetition factor of the SRS resource; andthe symbol └ ┘ represents rounding down.

n_(symbol)−l_(start) ^(SRS) represents a difference between a number ofa symbol in the slot and a number of the starting symbol of the SRSresource, and may be used as a separate variable, or may be obtained byusing another expression, for example, determined based on a number of asymbol in a subframe or a frame, the starting symbol of the SRSresource, and a subframe number.

└(n_(f)×N_(frame) ^(slot,μ)+n_(s))/T_(SRS)┘ represents a sequence numberof the current slot in all slots that can be used to send the SRS in aframe period, and may be obtained through calculation by using anotherequivalent expression. N_(symb) ^(SRS)·└(n×N_(frame)^(slot,μ)+n_(s))/T_(SRS)┘ represents a quantity of all symbols that canbe used to send the SRS in a frame period by the current slot, and maybe obtained through calculation by using another equivalent expression.

Optionally, n_(SRS) in the formula (1) may be a calculation method in acase, and it is not excluded that n_(SRS) is calculated according toanother formula in another case.

2. Aperiodic SRS Resource.

(1) It is assumed that the aperiodic SRS resource supports onlyintra-slot frequency hopping.

In this case, n_(SRS) represents a count of positions at which an SRSresource triggered this time is transmitted on a same subcarrier andcontinuous symbols. n_(SRS) may be determined through calculation basedon the following parameters: a starting symbol of the SRS resource in aslot, a symbol number, and a repetition factor (denoted as L_(r)) of theSRS resource.

Specifically, n_(SRS) may be determined through calculation according tothe following formula (2):n _(SRS)=└(n_(symbol) −l _(start) ^(SRS) )/L_(r)┘  (2)

Optionally, a quantity of symbols for SRS transmission is the smallerone of a quantity of symbols of the SRS resource and a product of atotal quantity of hops and the repetition factor. Therefore, when thequantity of symbols N_(symb) ^(SRS) of the SRS resource is less than theproduct K·N of the total quantity of hops and the repetition factor, anSRS is sent for times of only the quantity N_(symb) ^(SRS) of symbols ofthe SRS resource, that is, transmission is not performed on all hops.Alternatively, when the quantity N_(symb) ^(SRS) of symbols of the SRSresource is greater than the product K·N of the total quantity of hopsand the repetition factor, an SRS is transmitted only in K·N symbols ofthe SRS resource, and the SRS is not transmitted in a remaining symbolof the SRS resource. Optionally, the remaining symbol of the SRSresource may be used to transmit another uplink channel (for example, aPUSCH) or may not be used for transmission, or may be used to transmitanother SRS.

n_(symbol)−l_(start) ^(SRS) represents a difference between a number ofa symbol in the slot and a number of the starting symbol of the SRS, andmay be used as a separate variable, or may be obtained by using anotherexpression, for example, determined based on a number of a symbol in asubframe or a frame, the starting symbol of the SRS, and a subframenumber. The slot herein is determined based on the time intervaldescribed in step 210 and the resource on which the PDCCH or the CORESETthat carries the DCI used to trigger SRS transmission is located.

For example, the constraint condition may be expressed as the followingformula (3):

$\begin{matrix}{0 \leq n_{SRS} \leq \{ {{N_{symb}^{SRS}/L_{r}},{{\overset{B_{SRS}}{\prod\limits_{b^{\prime} = {b_{hop} + 1}}}N_{b}} - 1}} \}} & (3)\end{matrix}$

Alternatively, the constraint condition may be expressed as thefollowing formula (4):

$\begin{matrix}{n_{SRS} = \{ {{{\overset{B_{SRS}}{\prod\limits_{b^{\prime} = {b_{hop} + 1}}}N_{b^{\prime}}} - 1},\lfloor {( {n_{symbol} - l_{start}^{SRS}} )/L_{r}} \rfloor} \}} & (4)\end{matrix}$

(2) It is assumed that the aperiodic SRS resource supports intra-slotfrequency hopping and inter-slot frequency hopping.

In this case, n_(SRS) represents a count of positions at which an SRSresource triggered this time is transmitted on a same subcarrier andcontinuous symbols. n_(SRS) may be determined through calculation basedon the following parameters: a starting symbol of the SRS resource, aquantity of symbols of the SRS resource, a repetition factor of the SRSresource, a symbol number, a time difference between triggering DCI anda current slot, and a time domain offset. The time domain offsetdescribed herein is the time interval in step 210 in the foregoingdescription.

Specifically, n_(SRS) may be determined through calculation according tothe following formula (5):n _(SRS)=└(N_(symb) ^(SRS)·(n _(s) ^(Δ) −T _(offset))+n _(symbol) −l_(start) ^(SRS))/L_(r)┘  (5)

Herein, a maximum value of n_(SRS) is a total quantity of hops.

n_(symbol)−l_(start) ^(SRS) represents a difference between a number ofa symbol in the slot and a number of the starting symbol of the SRS, andmay be used as a separate variable, or may be obtained according toanother expression, for example, determined based on a number of asymbol in a subframe or a frame, the starting symbol of the SRS, and asubframe number.

n_(s) ^(Δ) is the time difference between DCI triggering and the currentslot.

(n_(s) ^(Δ)−T_(offset)) represents a difference between a number of thecurrent slot and a number of a slot in which the aperiodic SRS istransmitted for the first time, and may be obtained through calculationby using another equivalent method.

N_(symb) ^(SRS)·(n_(s) ^(Δ)−T_(offset)) represents a quantity of allsymbols that can be used to transmit the aperiodic SRS starting from thefirst time of transmission of the aperiodic SRS until the current slot,and may be obtained through calculation according to another equivalentexpression.

After determining n_(SRS) the terminal device can determine, based onn_(SRS) at least one frequency domain resource (referred to as the firstfrequency domain resource in this application) to which the SRS resourceis mapped in the current slot.

230. The terminal device sends an SRS to the network device on thedetermined at least one first frequency domain resource.

After the terminal device determines the at least one first frequencydomain resource to which the SRS resource is mapped in the current slotin step 220, the terminal device sends the SRS to the network device onthe at least one first frequency domain resource in step 230.

A person skilled in the art should understand that the process in whichthe terminal device sends the SRS to the network device on the at leastone first frequency domain resource is a frequency hopping process.

In this embodiment of this application, the network device can support aplurality of frequency hopping manners by configuring the repetitionfactor of the SRS resource. For example, the network device can supportinter-slot frequency hopping, inter-slot frequency hopping and frequencyhopping on each symbol in a slot, inter-slot frequency hopping andfrequency hopping on every two symbols in a slot, and frequency hoppingof an aperiodic SRS. This can improve frequency hopping flexibility.

In the method 200, the terminal device sends the SRS to the networkdevice on the determined at least one first frequency domain resource.

Optionally, the terminal device may send the SRS on each of the at leastone first frequency domain resource. Alternatively, to reduce a time formeasuring the total bandwidth to be measured, this application furtherprovides some frequency hopping manners below, so that the terminaldevice can send the SRS on some resource blocks (RB) of the at least onefirst frequency domain resource.

Manner 1

The terminal device determines, based on the first configurationinformation and second configuration information, at least one secondfrequency domain resource to which the SRS resource is mapped in thefirst time unit, where the second frequency domain resource is a part ofthe first frequency domain resource. The terminal device sends the SRSto the network device on the at least one second frequency domainresource.

In Manner 1, in addition to configuring the slot-level time domainparameter and the symbol-level parameter time domain that are indicatedby the first configuration information, the network device furtherconfigures the second configuration information. Based on the firstconfiguration information and the second configuration information, theterminal device can determine the at least one second frequency domainresource based on the at least one first frequency domain resource. Thesecond frequency domain resource is a part of the first frequency domainresource.

Optionally, the second configuration information is used to indicate anSRS bandwidth parameter and an SRS bandwidth position parameter.

It should be noted that, the SRS bandwidth parameter is used todetermine a bandwidth occupied by the second frequency domain resource.The SRS bandwidth position parameter is used to determine a position ofthe bandwidth occupied by the second frequency domain resource in abandwidth occupied by the first frequency domain resource.

In the following description, the SRS bandwidth parameter is denoted asb_(subband), and the SRS bandwidth position parameter is denoted asb_(subband) ^(offset).

It may be understood that, b_(subband) is actually used to configure asize of a bandwidth actually used when the terminal device sends theSRS. A value range of b_(subband) is B_(SRS)≤b_(subband)≤3, and aspecific value of the bandwidth configured by b_(subband) may beobtained by querying an SRS bandwidth configuration table.

b_(subband) ^(offset) is used to configure a position, in the SRSbandwidth, of the bandwidth actually used when the terminal device sendsthe SRS. A value range of b_(subband) ^(offset) is 0≤b_(subband)^(offset)≤Π_(b=B) _(SRS) ₊₁ ^(b) ^(subband) N_(b)−1. If one user-levelSRS bandwidth includes a maximum of k bandwidths corresponding tob_(subband), a specific value of b_(subband) ^(offset) should be0≤b_(subband) ^(offset)≤k, where k is a positive integer.

The following describes an example of a configuration table applicableto this embodiment of this application, referring to Table 10.

TABLE 10 B_(SRS) = 0 B_(SRS) = 1 B_(SRS) = 2 B_(SRS) = 3 C_(SRS)m_(SRS, 0) N₀ m_(SRS, 1) N₁ m_(SRS, 2) N₂ m_(SRS, 3) N₃ 0 4 1 4 1 4 1 41 1 8 1 4 2 4 1 4 1 2 12 1 4 3 4 1 4 1 3 16 1 4 4 4 1 4 1 4 16 1 8 2 4 24 1 5 20 1 4 5 4 1 4 1 6 24 1 4 6 4 1 4 1 7 24 1 12 2 4 3 4 1 8 28 1 4 74 1 4 1 9 32 1 16 2 8 2 4 2 10 36 1 12 3 4 3 4 1 11 40 1 20 2 4 5 4 1 1248 1 16 3 8 2 4 2 13 48 1 24 2 12 2 4 3 14 52 1 4 13 4 1 4 1 15 56 1 282 4 7 4 1 16 60 1 20 3 4 5 4 1 17 64 1 32 2 16 2 4 4 18 72 1 24 3 4 6 41 19 72 1 36 2 12 3 4 1 20 76 1 4 19 4 1 4 1 21 80 1 40 2 20 2 4 5 22 881 44 2 11 4 4 1 23 96 1 32 3 16 2 4 4 24 96 1 48 2 24 2 4 6 25 104 1 522 4 13 4 1 26 112 1 56 2 28 2 4 7 27 120 1 60 2 20 3 4 5 28 120 1 40 3 85 4 2 29 120 1 24 5 12 2 4 1 30 128 1 64 2 32 2 4 8 31 128 1 64 2 16 4 44 32 128 1 16 8 8 2 4 2 33 132 1 44 3 4 11 4 1 34 136 1 68 2 4 17 4 1 35144 1 72 2 36 2 4 9 36 144 1 48 3 24 2 12 2 37 144 1 48 3 16 3 4 4 38144 1 16 9 8 2 4 2 39 152 1 76 2 4 19 4 1 40 160 1 80 2 40 2 4 10 41 1601 80 2 20 4 4 5 42 160 1 32 5 16 2 4 4 43 168 1 84 2 28 3 4 7 44 176 188 2 44 2 4 11 45 184 1 92 2 4 23 4 1 46 192 1 96 2 48 2 4 12 47 192 196 2 24 4 4 6 48 192 1 64 3 16 4 4 4 49 192 1 24 8 8 3 4 2 50 208 1 1042 52 2 4 13 51 216 1 108 2 36 3 4 9 52 224 1 112 2 56 2 4 14 53 240 1120 2 60 2 4 15 54 240 1 80 3 20 4 4 5 55 240 1 48 5 16 3 8 2 56 240 124 10 12 2 4 3 57 256 1 128 2 64 2 4 16 58 256 1 128 2 32 4 4 8 59 256 116 16 8 2 4 2 60 264 1 132 2 44 3 4 11 61 272 1 136 2 68 2 4 17 62 272 1136 2 44 4 4 11 63 272 1 16 17 8 2 4 2

The following describes an example with reference to FIG. 5.

FIG. 5 is a schematic diagram of determining the second frequency domainresource.

In FIG. 5, user-level configuration parameters configured by the networkdevice are C_(SRS)=24 and B_(SRS)=1. If the network device configuresthat b_(subband)=2, and b_(subband) ^(offset)=1, the terminal devicesends the SRS only on a subband of a user-level SRS bandwidth. Thesubband of the user-level SRS bandwidth is the second frequency domainresource described in this embodiment of this application.

A quantity of resource blocks RBs occupied by the second frequencydomain resource in frequency domain is represented as m_(SRS,subband),and m_(SRS,subband) may be obtained by querying the SRS bandwidthconfiguration table.

It may be understood that, FIG. 5 describes an example in which there isonly one second frequency domain resource, and when there are at leasttwo second frequency domain resources, a start frequency domain positionof the at least two second frequency domain resources may be determinedthrough calculation according to the following formula (6):

$\begin{matrix}{k_{0}^{(p)} = {{\overset{\_}{k}}_{0}^{(p)} + {b_{subband}^{offset}M_{{sc},b_{subband}}^{RS}} + {\sum\limits_{b = 0}^{B}{K_{TC}M_{{sc},b}^{RS}n_{b}}}}} & (6)\end{matrix}$

Optionally, in Manner 1, concepts of b_(subband) and B_(SRS) may beinterchangeable. B_(SRS) is used to indicate the size of the bandwidthactually used when the terminal device sends the SRS. b_(subband) isused to indicate the user-level SRS bandwidth.

Manner 2

The terminal device determines, based on the first configurationinformation and third configuration information, at least one thirdfrequency domain resource to which the SRS resource is mapped in thefirst time unit, where a set including the at least one third frequencydomain resource is a subset of a set including the at least one firstfrequency domain resource. The terminal device sends the SRS to thenetwork device on the at least one third frequency domain resource.

In Manner 2, in addition to configuring the first configurationinformation as described above, the network device further configuresthe third configuration information. Based on the first configurationinformation and the third configuration information, the terminal devicecan determine the at least one third frequency domain resource based onthe at least one first frequency domain resource. The set including theat least one third frequency domain resource is a subset of the setincluding the at least one first frequency domain resource in one ormore time units.

In Manner 2, the third configuration information may be used to indicatea quantity t_(symbol) ^(SRS) of reference symbols.

In this application, the quantity t_(symbol) ^(SRS) of reference symbolsis used to determine at least one first frequency domain resourceoccupied by the SRS resource in the first time unit (for example, aslot), where t_(symbol) ^(SRS)>1 and is an integer.

It should be noted that, a value range of the quantity t_(symbol) ^(SRS)of reference symbols is greater than or equal to the quantity N_(symb)^(SRS) of symbols of the SRS resource.

Specifically, in Manner 2, for a periodic or semi-persistent SRSresource, the terminal device may calculate n_(SRS) according to thefollowing formula (7):n _(SRS)=└(t _(symbol) ^(SRS)·└(n×N _(frame) ^(slot,μ) +n _(s))/T _(SRS)┘+n _(symbol) −l _(start) ^(SRS))/L _(r)┘  (7)

A person skilled in the art may understand that, comparing the formula(7) with the foregoing formula (1), the parameter N_(symb) ^(SRS) ischanged to t_(symbol) ^(SRS), and other parameters for calculatingn_(SRS) remain the same. N_(symb) ^(SRS) is a quantity of symbols thatcan be occupied by the SRS resource in a slot. Therefore, when a valueof t_(symbol) ^(SRS) is greater than that of N_(symb) ^(SRS), adifferent value of n_(SRS) is obtained through calculation.

In other words, according to the formula (7), frequency hopping overt_(symbol) ^(SRS) symbols is calculated, but the terminal deviceactually sends the SRS only on N_(symb) ^(SRS) symbols. In other words,there are (t_(symbol) ^(SRS)−N_(symb) ^(SRS)) symbols in which no SRS issent. Therefore, the terminal device can send the SRS only on a part ofthe first frequency domain resource. The part of the first frequencydomain resource herein is the at least one third frequency domainresource described in this application. In other words, the setincluding the at least one third frequency domain resource is actually asubset of the set including the at least one first frequency domainresource.

The following describes an example with reference to FIG. 6.

FIG. 6 is a schematic diagram of determining the third frequency domainresource. As shown in FIG. 6, if the network device configures thatN_(symb) ^(SRS)=4, for an SRS resource including four symbols, there arefour first frequency domain positions in a slot. In this case, theterminal device sends the SRS on each first frequency domain resource.If the network device configures that N_(symb) ^(SRS)=2, and theterminal device performs calculation based on that one slot includest_(symbol) ^(SRS)=4 symbols for frequency hopping, but the terminaldevice actually sends the SRS only in N_(symb) ^(SRS)=2 symbols, theterminal device can also send the SRS on some RBs.

It should be understood that, Manner 2 is not applicable to an aperiodicSRS resource that supports only intra-slot frequency hopping. Manner 2is applicable to an aperiodic SRS resource that supports intra-slotfrequency hopping and inter-slot frequency hopping. For example, aformula for calculating n_(SRS) may be a formula (8):n=└(t _(SRS) ^(symbol)·(n _(s) ^(Δ) −T _(offset))+n _(symbol) −l_(start) ^(SRS))/L _(r)┘  (8)

In this embodiment of this application, if an aperiodic SRS resourcesupports only intra-slot frequency hopping, when the total quantity ofhops K is greater than the quantity of symbols of the SRS resource, andsending is performed only at first t_(symbol) ^(SRS) hops, measurementof the total bandwidth to be measured may be inaccurate because thefirst t_(symbol) ^(SRS) symbol hops may not be evenly distributed in thetotal bandwidth to be measured.

It should be noted that, in this embodiment of this application, thetotal quantity of hops corresponding to the total bandwidth to bemeasured is denoted as K,

$K = {\prod\limits_{b^{\prime} = {b_{hop} + 1}}^{B_{SRS}}{N_{b^{\prime}}.}}$In other words, the total bandwidth to be measured includes Knon-overlapping frequency resources. A bandwidth of each of the Knon-overlapping frequency resources is an SRS bandwidth.

With reference to FIG. 7, the following describes an example in whichmeasurement of the total bandwidth to be measured is inaccurate when thetotal quantity of hops is greater than the quantity of symbols of theSRS resource.

It is assumed that bandwidth configuration parameters in Table 11 areused.

TABLE 11 B_(SRS) = 0 B_(SRS) = 1 B_(SRS) = 2 B_(SRS) = 3 m_(SRS, 0) N₀m_(SRS, 1) N₁ m_(SRS, 2) N₂ m_(SRS, 3) N₃ 48 1 16 3 8 4 2

For example, if the network device configures that b_(hop)=0, B_(SRS)=3,t_(symbol) ^(SRS)=4, and n_(RRC)=0, four hops at which the terminaldevice measures the total bandwidth to be measured may be shown in FIG.7. FIG. 7 is a schematic diagram of sending an SRS by the terminaldevice. It can be learned from FIG. 7 that, after the terminal deviceperforms the measurement at the four hops, a frequency hopping patternis distributed in only first ¾ of the total bandwidth to be measured.

For another example, if the network device configures that b_(hop)=0,B_(SRS)=3, t_(symbol) ^(SRS)=2, and n_(RRC)=0, two hops at which theterminal device measures the total bandwidth to be measured may be shownin FIG. 8. FIG. 8 is another schematic diagram of sending an SRS by theterminal device. Similarly, after the terminal device performs themeasurement at the two hops, a frequency hopping pattern is distributedin only first ½ of the total bandwidth to be measured.

For the cases shown in FIG. 7 and FIG. 8, for relatively high-frequencybands related to no frequency hopping pattern, a channel measurementresult can be obtained only through extrapolation, and thereforeaccuracy is relatively low.

Therefore, for this problem that occurs when an SRS is sent on anaperiodic SRS resource, this application provides some solutions, sothat the frequency hopping pattern can evenly cover, as much aspossible, the total bandwidth to be measured, thereby improvingmeasurement accuracy.

Solution 1

A frequency separation between a first frequency domain position of thebandwidth occupied by the at least one first frequency domain resourceand a first frequency domain position of the total bandwidth to bemeasured is not greater than a first threshold, and/or a frequencyseparation between a second frequency domain position of the bandwidthoccupied by the at least one first frequency domain resource and asecond frequency domain position of the total bandwidth to be measuredis not greater than a second threshold. A satisfied relationship betweenthe at least one first frequency domain resource and the total bandwidthto be measured is referred to as a constraint condition 1 below.

Herein, the first frequency domain position of the bandwidth occupied bythe at least one first frequency domain resource may be a frequencydomain position of a subcarrier corresponding to a lowest, highest, orcenter frequency in the bandwidth occupied by the at least one firstfrequency domain resource, or may be another frequency domain positionadjacent to the frequency domain position of the subcarriercorresponding to the lowest, highest, or center frequency. The secondfrequency domain position of the bandwidth occupied by the at least onefirst frequency domain resource may be a frequency domain position of asubcarrier corresponding to a highest, lowest, or center frequency inthe bandwidth occupied by the at least one first frequency domainresource, or may be another frequency domain position adjacent to thefrequency domain position of the subcarrier corresponding to thehighest, lowest, or center frequency.

Similarly, the first frequency domain position of the total bandwidth tobe measured may be a frequency domain position of a subcarriercorresponding to a lowest, highest, or center frequency in the totalbandwidth to be measured, or may be another frequency domain positionadjacent to the frequency domain position of the subcarriercorresponding to the lowest, highest, or center frequency. The secondfrequency domain position of the total bandwidth to be measured may be afrequency domain position of a subcarrier corresponding to a highest,lowest, or center frequency in the total bandwidth to be measured, ormay be another frequency domain position adjacent to the frequencydomain position of the subcarrier corresponding to the highest, lowest,or center frequency.

The first threshold may be determined based on at least one of thefollowing parameters: K, N, N_(symb) ^(SRS), the total bandwidth to bemeasured, and the user-level SRS bandwidth, and/or the second thresholdmay also be determined based on at least one of the followingparameters: K, N, N_(symb) ^(SRS), the total bandwidth to be measured,and the user-level SRS bandwidth.

It may be understood that in the design idea of Solution 1, thefrequency separation between the first frequency domain position of thebandwidth occupied by the at least one first frequency domain resourceand the first frequency domain position of the total bandwidth to bemeasured should be not greater than the first threshold, and/or afrequency bandwidth between the second frequency domain position of thebandwidth occupied by the at least one first frequency domain resourceand the second frequency domain position of the total bandwidth to bemeasured should be not greater than the second threshold.

In other words, according to the constraint condition 1, the at leastone first frequency domain resource is not distributed only in a part ofthe total bandwidth to be measured, but cover a larger bandwidth rangeas much as possible, so that the measurement accuracy can be improved.

Specifically, there are several manners as described below in which arelationship between the determined at least one first frequency domainresource and the total bandwidth to be measured meet the constraintcondition 1 described in Solution 1.

Manner A

In Manner A, it is assumed that a total of K hops are required forcompleting measurement of the total bandwidth to be measured, where

$K = {\prod\limits_{b^{\prime} = {b_{hop} + 1}}^{B_{SRS}}{N_{b^{\prime}}.}}$The K hops correspond to a total of

$K = {\prod\limits_{b^{\prime} = {b_{hop} + 1}}^{B_{SRS}}N_{b^{\prime}}}$nodes at a bottom layer of a frequency hopping tree-shaped structure.The K nodes are evenly divided into N_(symbol) ^(SRS)/_(r) segments.Each segment is spaced by

${{round}( \frac{K}{t_{symbol}^{SRS}} )}{\cdot i}$nodes with another one. An i^(th) segment is located between nodes

${{{round}( \frac{K}{N_{symb}^{SRS}/L_{r}} )} \cdot i},{{{round}( \frac{K}{N_{symb}^{SRS}/L_{r}} )} \cdot {( {i + 1} ).}}$In a process of N_(symb) ^(SRS)/L_(r) hops, a counter flag(i) and a hopcounter NUM_(i) are set, where i∈└0,N_(symb) ^(SRS)/L_(r)). Initially,flag(i)=0, and NUM_(i)=1.

For a K^(th) hop, NU/M_(k) is calculated according to the followingsteps.

(1) A position

$n_{temp} = {\sum\limits_{b = 0}^{B_{SRS}}\lbrack {n_{b} \cdot {\prod\limits_{b^{\prime} = {b_{hop} + 1}}^{B_{SRS}}N_{b^{\prime}}}} \rbrack}$of a node (denoted as a node A below) corresponding to

$n_{SRS} = {{\sum\limits_{i = 0}^{k - 1}{NUM_{i}}} - 1}$is calculated according to a formula (9).

$\begin{matrix}{\mspace{779mu}(9)} \\{n_{SRS} =} \\{\mspace{50mu}\{ \begin{matrix}{{{2N_{SP}n_{f}} + {2( {N_{SP} - 1} )\lfloor \frac{n_{s}}{10} \rfloor} + \lfloor \frac{T_{offset}}{T_{offset\_ max}} \rfloor},} & \begin{matrix}{{for}\mspace{14mu} 2\mspace{14mu}{ms}\mspace{14mu}{SRS}\mspace{14mu}{periodicity}} \\{{of}\mspace{14mu}{frame}\mspace{14mu}{structure}\mspace{14mu}{type}\mspace{14mu} 2}\end{matrix} \\{\lfloor {( {{n_{f} \times 10} + \lfloor {n_{s}/2} \rfloor} )/T_{SRS}} \rfloor,} & {otherwise}\end{matrix} }\end{matrix}$

(2) Assuming that the node A is located at the i^(th) segment, that is,

$\lfloor \frac{n_{temp}}{N_{symb}^{SRS}/L_{r}} \rfloor \in {\lbrack {i,{i + 1}} ).}$If flag(i)=0, it is considered that a frequency hopping position islocated at the node A, and step (3) is performed, or if flag(i)=1,NUM_(k−1)=NUM_(k+1), and step (1) is performed again to recalculate thefrequency hopping position.

(3) flag(i) is set to 1, and the process ends.

In addition, in Solution 1, a start position of a subband for sendingthe SRS is calculated according to the following formula (10):

$\begin{matrix}{n_{SRS} = \{ \begin{matrix}{\lfloor {( {n_{symbol} - {N_{start}^{SRS}/L_{r}}} )/L_{r}} \rfloor,} & {{\prod\limits_{b^{\prime} = {b_{hop} + 1}}^{B_{SRS}}N_{b^{\prime}}}<={N_{symb}^{SRS}/L_{r}}} \\{{{\sum\limits_{i = 0}^{\lfloor{{({n_{symbol} - {N_{start}^{SRS}/L_{r}}})}/L_{r}}\rfloor}{NUM}_{i}} - 1},} & {otherwise}\end{matrix} } & (10)\end{matrix}$

The following describes, by using an example, the frequency hoppingpattern determined according to the method in Solution 1.

First, it is assumed that bandwidth configurations shown in Table 12 areused.

TABLE 12 B_(SRS) = 0 B_(SRS) = 1 B_(SRS) = 2 B_(SRS) = 3 m_(SRS, 0) N₀m_(SRS, 1) N₁ m_(SRS, 2) N₂ m_(SRS, 3) N₃ 48 1 16 3 8 2 4 2

If the network device configures that b_(hop)=0, B_(SRS)=3, N_(symb)^(SRS)/L_(r)=4, and n_(RRC)=0, NUM₀=1, NUM₁=1, NUM₂=1, and NUM₃=3 may beobtained through calculation according to the method in Solution 1. Forthe frequency hopping pattern, refer to FIG. 9. FIG. 9 shows a frequencyhopping pattern based on a configuration according to this application.

If the network device configures that b_(hop)=0, B_(SRS)=3, N_(symb)^(SRS)/L_(r)=2, and n_(RRC)=0, NUM₀=1 and NUM₁=2 may be obtained throughcalculation according to the method in Solution 1. For the frequencyhopping pattern, refer to FIG. 10. FIG. 10 shows a frequency hoppingpattern based on another configuration according to this application.

It can be learned from FIG. 9 and FIG. 10 that, for N_(symb)^(SRS)/L_(r) hops, according to the method provided in Solution 1, itcan be ensured that N_(symb) ^(SRS)/L_(r) frequency domain positions atwhich the terminal device sends the SRS are located in N_(symb)^(SRS)/L_(r) frequency bands that are evenly spaced. A frequencyseparation between a subcarrier corresponding to a lowest frequency in afrequency hopping bandwidth and a lowest subcarrier on the SRS resourceis not greater than a threshold (that is, the first threshold). Afrequency separation between a subcarrier corresponding to a highestfrequency in the frequency hopping bandwidth and a subcarriercorresponding to a highest frequency on the SRS resource is not greaterthan a threshold (denoted as the second threshold herein for ease ofdistinguishing from the first threshold).

It may be understood that, the first threshold and the second thresholdmay be equal or unequal. For example, the first threshold and the secondthreshold may both be equal to

${\lbrack {{{round}( \frac{K}{N_{symb}^{SRS}/L_{r}} )} - 1} \rbrack \cdot B_{SRS}},$that is, the frequency separation between the subcarrier correspondingto the lowest frequency in the total bandwidth to be measured and thesubcarrier corresponding to the lowest frequency on the SRS resource isnot greater than

$\lbrack {{{round}( \frac{K}{N_{symb}^{SRS}/L_{r}} )} - 1} \rbrack$user-level SRS bandwidths. Alternatively, the first threshold and thesecond threshold may be set separately. This is not limited in thisembodiment of this application.

Solution 2

A frequency separation between third frequency domain positions of twoadjacent first frequency domain resources in the at least one firstfrequency domain resource is not greater than a third threshold. Thethird threshold is determined based on at least one of the followingparameters: K, N_(symb) ^(SRS), the total bandwidth to be measured, andthe user-level SRS bandwidth.

Herein, the third frequency domain position may be a frequency domainposition at which a subcarrier corresponding to a lowest, highest, orcenter frequency in the bandwidth occupied by the first frequency domainresource is located; a frequency domain position at which a subcarriercorresponding to a highest, lowest, or center frequency in the bandwidthoccupied by the first frequency domain resource is located; or afrequency domain position at which a subcarrier corresponding to anyfrequency between the lowest frequency and the highest frequency islocated.

In Solution 2, it is still assumed that a total of K hops are requiredfor completing measurement of the total bandwidth to be measured, where

$K = {\prod\limits_{b^{\prime} = {b_{hop} + 1}}^{B_{SRS}}{N_{b^{\prime}}.}}$

For an aperiodic SRS resource, it is assumed that N_(symb) ^(SRS)/L_(r)hops are required in a slot. In the total bandwidth to be measured,subcarrier positions f_(k) to which N_(symb) ^(SRS)/L_(r) SRSs aremapped are correspondingly designed, where k∈└1,N_(symb) ^(SRS)/L_(r)┘.In frequency domain, a frequency separation between subcarriers to whichadjacent SRS resources are mapped is denoted as Δf_(k), wherek∈└1,N_(symb) ^(SRS)/L_(r)−1┘.

In an optional solution, the frequency separation Δf_(k) is determinedbased on the quantity N_(symb) ^(SRS)/L_(r) of hops in a slot and thetotal quantity of hops K, and N_(symb) ^(SRS)/L_(r)−1 frequencyseparations Δf_(k) should not be greater than the third threshold.

For example, the third threshold may be the user-level bandwidthB_(SRS), that is, |Δf_(i)−Δf_(j)|≤B_(SRS).

According to Solution 2, it can be ensured that frequency domainpositions for N_(symb) ^(SRS)/L_(r) hops are evenly distributed in thetotal bandwidth to be measured, and two frequency separations betweenthird frequency domain positions of adjacent frequency domain resourceson which the terminal device sends the SRS are basically the same.

Optionally, a starting subcarrier to which the SRS resource is mappedmay be calculated according to the following formulas (11) to (13):

$\begin{matrix}{\overset{\_}{n} = \{ {\begin{matrix}\begin{matrix}( {n_{start} + {{round}\{ \lbrack ( {{\frac{N_{symb}^{SRS}/L_{r}}{2} \cdot n_{SRS}} + \lfloor \frac{n_{SRS}}{2} \rfloor} )  }}  \\{{ { {{mod}( {N_{symb}^{SRS}/L_{r}} )} \rbrack \cdot ( \frac{K - 1}{{N_{symb}^{SRS}/L_{r}} - 1} )} ){mod}\mspace{11mu} K},}\end{matrix} & {n_{start} = {{0\mspace{14mu}{or}\mspace{14mu} K} - 1}} \\\begin{matrix}( {n_{start} + {{round}\{ \lbrack ( {{\frac{N_{symb}^{SRS}/L_{r}}{2} \cdot n_{SRS}} + \lfloor \frac{n_{SRS}}{2} \rfloor} )  }}  \\{{ { {{mod}( {N_{symb}^{SRS}/L_{r}} )} \rbrack \cdot ( \frac{K}{N_{symb}^{SRS}/L_{r}} )} ){mod}\mspace{11mu} K},}\end{matrix} & {otherwise}\end{matrix}\mspace{20mu}{where}} } & (11) \\{\mspace{79mu}{n_{start} = {\sum\limits_{b = 0}^{B_{SRS}}\lbrack {( {\lfloor {4{n_{RRC}/m_{{SRS},b}}} \rfloor{mod}\mspace{11mu} N_{b}} ) \cdot {\prod\limits_{b^{\prime} = {b + 1}}^{B_{SRS}}N_{b^{\prime}}}} \rbrack}}} & (12) \\{\mspace{79mu}{n_{SRS} = \lfloor {( {n_{symbol} - N_{sybm}^{SRS}} )/L_{r}} \rfloor}} & (13)\end{matrix}$

Alternatively, a starting subcarrier to which the SRS resource is mappedmay be calculated according to the following formulas (14) and (15):

$\begin{matrix}{\mspace{79mu}{k_{0}^{(p)} = {{\overset{\_}{k}}_{0}^{(p)} + {K_{TC}M_{{sc},B_{SRS}}^{RS}\overset{\_}{n}}}}} & (14) \\{\overset{\_}{n} = \{ \begin{matrix}{{( {n_{start} + {{round}( {n_{SRS} \cdot \frac{K - 1}{{N_{symb}^{SRS}/L_{r}} - 1}} )}} ){mod}\mspace{11mu} K},} & \begin{matrix}{n_{start} = {0\mspace{14mu}{or}}} \\{n_{start} = {K - 1}}\end{matrix} \\{{( {n_{start} + {{round}( {n_{SRS} \cdot \frac{K}{N_{symb}^{SRS}/L_{r}}} )}} ){mod}\mspace{11mu} K},} & {otherwise}\end{matrix} } & (15)\end{matrix}$

It should be understood that, formulas for calculating the frequencydomain positions of the subcarriers to which the SRS resource is mappedin Solution 2 are not limited to the formulas above, and a formula inanother form may also be used.

With reference to FIG. 11 and FIG. 12, the following describes, by usingan example, the frequency hopping pattern determined according toSolution 2.

First, it is assumed that bandwidth configurations shown in Table 13 areused.

TABLE 13 B_(SRS) = 0 B_(SRS) = 1 B_(SRS) = 2 B_(SRS) = 3 m_(SRS, 0) N₀m_(SRS, 1) N₁ m_(SRS, 2) N₂ m_(SRS, 3) N₃ 48 1 16 3 8 2 4 2

For example, if the network device configures that b_(hop)=0, B_(SRS)=3,N_(symb) ^(SRS)/L_(r)=4, and n_(RRC)=0, and formulas (11) to (13) areused for calculation, a determined frequency hopping pattern is shown inFIG. 11. FIG. 11 shows an example of a frequency hopping pattern basedon a configuration. If formulas (14) and (15) are used for calculation,a determined frequency hopping pattern is shown in FIG. 12. FIG. 12shows another example of a frequency hopping pattern based on aconfiguration.

It can be seen from FIG. 11 and FIG. 12 that, the frequency hoppingpattern is determined according to the solution provided in Solution 2,and after four hops, the frequency domain positions at which theterminal device sends the SRS are more evenly distributed in the entirebandwidth. This can improve channel measurement accuracy.

For another example, if the network device configures that b_(hop)=0,B_(SRS)=3, N_(symb) ^(SRS)/L_(r)=2, and n_(RRC)=0, and formulas (11) to(13) are used for calculation, a determined frequency hopping pattern isshown in FIG. 13. FIG. 13 shows an example of a frequency hoppingpattern based on a configuration. If formulas (14) and (15) are used forcalculation, a determined frequency hopping pattern is shown in FIG. 14.FIG. 14 shows another example of a frequency hopping pattern based on aconfiguration according to this application.

Manner 3

For an SRS resource including N_(symb) ^(SRS) symbols, the networkdevice performs the following configuration by default:

-   -   (1) The total quantity of hops K is not equal to N_(symb)        ^(SRS);    -   (2) the total quantity of hops K is greater than N_(symb)        ^(SRS); or    -   (3) the total quantity of hops K is less than N_(symb) ^(SRS).

In other words, the terminal device considers or assumes that theterminal device cannot receive indication information that is sent bythe network device and that is used to indicate that K is not equal toN_(symb) ^(SRS);

-   -   the terminal device considers or assumes that the terminal        device cannot receive indication information that is sent by the        network device and that is used to indicate that K is greater        than N_(symb) ^(SRS); or    -   the terminal device considers or assumes that the terminal        device cannot receive indication information that is sent by the        network device and that is used to indicate that K is less than        N_(symb) ^(SRS).

Based on the default configuration, if K is not equal to N_(symb)^(SRS), K is greater than N_(symb) ^(SRS), or K is less than N_(symb)^(SRS), the terminal device does not send the SRS on an SRS resourceconfigured in a current slot.

It may be understood that, in Manner 3, only some RBs in the totalbandwidth to be measured are measured, which can reduce time formeasuring the total bandwidth.

Manner 4

The terminal device determines a frequency hopping pattern according tothe following formulas (16), (17), and (18), to send the SRS on someRBs.

$\begin{matrix}{\mspace{79mu}{k_{0}^{(p)} = {{\overset{\_}{k}}_{0}^{(p)} + {\sum\limits_{b = 0}^{B_{SRS}}{K_{TC} \cdot M_{{sc},b}^{RS} \cdot n_{b}}}}}} & (16) \\{n_{b} = \{ \begin{matrix}{\lfloor {4{n_{RRC}/m_{{SRS},b}}} \rfloor{mod}\mspace{11mu} N_{b}} & {otherwise} \\{\{ {{F_{b}( n_{SRS} )} + \lfloor {4{n_{RRC}/m_{{SRS},b}}} \rfloor} \}{mod}\mspace{11mu} N_{b}} & {b_{hop} < b \leq b_{minhop}}\end{matrix} } & (17) \\{{F_{b}( n_{SRS} )} = \{ \begin{matrix}{{( {N_{b}/2} )\lfloor \frac{n_{SRS}{mod}{\prod\limits_{b^{\prime} = b_{hop}}^{b}N_{b^{\prime}}}}{\prod\limits_{b^{\prime} = b_{hop}}^{b - 1}N_{b^{\prime}}} \rfloor} + \lfloor {n_{SRS}{mod}{\prod\limits_{b^{\prime} = b_{hop}}^{b}N_{b^{\prime}}}} \rfloor} & {{if}\mspace{14mu} N_{b}\mspace{14mu}{even}} \\{\lfloor {N_{b}/2} \rfloor\lfloor {n_{SRS}/{\prod\limits_{b^{\prime} = b_{hop}}^{b - 1}N_{b^{\prime}}}} \rfloor} & {{if}\mspace{14mu} N_{b}\mspace{14mu}{odd}}\end{matrix} } & (18)\end{matrix}$

In Manner 4, to implement even frequency hopping on some RBs, thenetwork device configures a parameter b_(minhop). A default setting ofb_(minhop) may be equal to B_(SRS). To be specific, if the networkdevice configures a value of b_(minhop), the terminal device uses thevalue configured for b_(minhop); or if the network device does notconfigure the value of b_(minhop), b_(minhop) is set to B_(SRS). Forexample, a bandwidth of a fourth frequency domain resource can bedetermined based on a bandwidth set configured by using C_(SRS). It canbe learned according to formula (17) that, frequency hopping isperformed only at (b_(hop)+1)^(th) to b_(minhop) ^(th) layers in an SRStree-shaped bandwidth structure, and is not performed at(b_(minhop)+1)^(th) to B_(SRS) ^(th) layers. In this case, the SRS canbe sent only on some RBs of the bandwidth occupied by each fourthfrequency domain resource. A bandwidth corresponding to some RBsdescribed herein is the bandwidth of the first frequency domain resourcedetermined based on B_(SRS).

With reference to FIG. 15 and FIG. 16, the following describes, by usingan example, the frequency hopping pattern determined according to themethod in Manner 4.

FIG. 15 shows a frequency hopping pattern based on a configurationaccording to an embodiment of this application. As shown in FIG. 15, ifC_(SRS)=24, and b_(minhop) and B_(SRS) are both set to 2, the bandwidthof the fourth frequency domain resource is the same as the bandwidth ofthe first frequency domain resource. Therefore, the SRS can be sent,through frequency hopping, on all RBs in a range of the total bandwidthto be measured.

FIG. 16 shows a frequency hopping pattern based on another configurationaccording to an embodiment of this application. As shown in FIG. 16, ifC_(SRS)=24, b_(minhop) is set to 1, and B_(SRS) is set to 2, thebandwidth of the fourth frequency domain resource is greater than thebandwidth of the first frequency domain resource. For example, in thisembodiment, if the bandwidth of the fourth frequency domain resource istwice the bandwidth of the first frequency domain resource, it isdetermined according to the formula (17) that different fourth frequencydomain resources are used for two consecutive times of SRS transmission,that is, frequency hopping is performed. However, a relative position ofa first frequency domain resource on which the SRS is actually sentremains unchanged on the fourth frequency domain resource, that is,frequency hopping is not performed. Therefore, the SRS may be sent,through frequency hopping, in a bandwidth of a first frequency domainresource in each fourth frequency domain resource in the range of thebandwidth to be measured. In other words, the SRS is sent on some RBs inthe range of the bandwidth to be measured, and it is further ensuredthat the RB blocks for sending the SRS are evenly distributed in therange of the bandwidth to be measured.

Optionally, the formulas (16) and (18) may have a different calculationmethod or expression form. This is not limited in the present invention.

Optionally, a value range of b in the formula (17) may be denoted as0−b_(max), for example, b_(max)=B_(SRS) or another values. A restrictivecondition of the formula (17) may undergo the following equivalentchange:

$\begin{matrix}{n_{b} = \{ {\begin{matrix}{\lfloor {4{n_{RRC}/m_{{SRS},b}}} \rfloor{mod}\mspace{11mu} N_{b}} & {b > {b_{minhop}\mspace{14mu}{or}\mspace{14mu} b} \leq b_{hop}} \\{\{ {{F_{b}( n_{SRS} )} + \lfloor {4{n_{RRC}/m_{{SRS},b}}} \rfloor} \}{mod}\mspace{11mu} N_{b}} & {b_{hop} < b \leq b_{minhop}}\end{matrix}\mspace{20mu}{or}} } & (19) \\{n_{b} = \{ \begin{matrix}{\lfloor {4{n_{RRC}/m_{{SRS},b}}} \rfloor{mod}\mspace{11mu} N_{b}} & {b > {b_{minhop}\mspace{14mu}{or}\mspace{14mu} b} \leq b_{hop}} \\{\{ {{F_{b}( n_{SRS} )} + \lfloor {4{n_{RRC}/m_{{SRS},b}}} \rfloor} \}{mod}\mspace{11mu} N_{b}} & {otherwise}\end{matrix} } & (20)\end{matrix}$

Alternatively, the value range of b is further limited in therestrictive condition, or another equivalent expression may be used.This is not limited in the present invention.

It should be noted that the symbol N_(symbol) ^(SRS) and the symbolN_(symbol) ^(SRS) represent a same meaning in this specification.

A predefinition may be specified in a communication protocol.

The indication information or the configuration information in thisembodiment of this application may be transmitted by using one piece ofsignaling, or transmitted by using a plurality of pieces of signaling.The signaling may be carried in RRC signaling, MAC CE signaling, or DCI.The transmission by using a plurality of pieces of signaling may meanthat the indication information or the configuration information isdivided into a plurality of parts, and each part is transmitted by usingone piece of signaling. Alternatively, a candidate set of the indicationinformation or the configuration information may be first configured byusing one piece of signaling, and then a piece of information in thecandidate set is indicated by another piece of signaling. Alternatively,a candidate set of the indication information or the configurationinformation may be first configured by using one piece of signaling,then a subset of the candidate set is indicated by a second piece ofsignaling, and a piece of information in the subset of the candidate setis indicated by a third piece of signaling. Optionally, the indicationinformation or the configuration information may alternatively beconfigured by using a combination of the foregoing plurality of methods.

The foregoing describes in detail the method for sending a referencesignal in the embodiment of this application with reference to FIG. 1 toFIG. 16. The following describes a terminal device and a network devicein the embodiments of this application with reference to FIG. 17 to FIG.20.

FIG. 17 is a schematic block diagram of a terminal device 500 accordingto an embodiment of this application. As shown in FIG. 17, the terminaldevice 500 includes a receiving unit 510, a processing unit 520, and asending unit 530.

The receiving unit 510 is configured to receive first configurationinformation of a sounding reference signal SRS resource from a networkdevice, where the first configuration information includes a repetitionfactor of the SRS resource, and the repetition factor of the SRSresource is a quantity N of positions at which the SRS resource ismapped to a same subcarrier and mapped to at least one continuous symbolin one time unit, where N≥1 and is an integer.

The processing unit 520 is configured to determine, based on the firstconfiguration information, at least one first frequency domain resourceto which the SRS resource is mapped in a first time unit.

The sending unit 530 is configured to send an SRS to the network deviceon the at least one first frequency domain resource.

The units in the terminal device 500 and other operations or functionsin this embodiment of this application are for a purpose of implementinga corresponding procedure performed by the terminal device in the methodfor sending a reference signal, and details are not described hereinagain.

FIG. 18 is a schematic block diagram of a network device 600 accordingto an embodiment of this application. As shown in FIG. 18, the networkdevice 600 includes a sending unit 610 and a receiving unit 620.

The sending unit 610 is configured to send first configurationinformation of an SRS resource to a terminal device, where the firstconfiguration information includes a repetition factor of the SRSresource, and the repetition factor of the SRS resource is a quantity Nof positions at which the SRS resource is mapped to a same subcarrierand mapped to at least one continuous symbol in one time unit, where N≥1and is an integer.

The receiving unit 620 is configured to receive an SRS that is sent bythe terminal device on at least one first frequency domain resource,where the at least one first frequency domain resource is a frequencydomain position that is determined by the terminal device based on thefirst configuration information and that is used for sending the SRS.

The units in the network device 600 and other operations or functions inthis embodiment of this application are for a purpose of implementing acorresponding procedure performed by the network device in the methodfor sending a reference signal. For brevity, details are not describedherein again.

FIG. 19 is a schematic structural diagram of a terminal device 700according to an embodiment of this application. As shown in FIG. 19, theterminal device 700 includes: one or more processors 701, one or morememories 702, and one or more transceivers 703. The processor 701 isconfigured to control the transceiver 703 to receive and send a signal.The memory 702 is configured to store a computer program. The processor701 is configured to invoke the computer program from the memory 702 andrun the computer program, so that the terminal device 700 performs themethod for sending a reference signal. For brevity, details are notdescribed herein again.

FIG. 20 is a schematic structural diagram of a network device 800according to an embodiment of this application. As shown in FIG. 20, thenetwork device 800 includes: one or more processors 801, one or morememories 802, and one or more transceivers 803. The processor 801 isconfigured to control the transceiver 803 to receive and send a signal.The memory 802 is configured to store a computer program. The processor801 is configured to invoke the computer program from the memory 802 andrun the computer program, so that the network device 800 performs themethod for sending a reference signal. For brevity, details are notdescribed herein again.

In addition, this application further provides a computer programproduct. The computer program product includes computer program code.When the computer program code is run on a computer, the computer isenabled to perform the corresponding procedure and/or operationperformed by the terminal device in the foregoing method for sending areference signal.

In addition, this application further provides a computer-readablemedium. The computer-readable medium stores program code. When thecomputer program code is run on a computer, the computer is enabled toperform the corresponding procedure and/or operation performed by theterminal device in the foregoing method for sending a reference signal.

In addition, this application further provides a chip system. The chipsystem includes a processor, configured for a terminal device toimplement a function in the foregoing method for sending a referencesignal, for example, receiving or processing data and/or information inthe foregoing method. In a possible design, the chip system furtherincludes a memory. The memory is configured to store a programinstruction and data necessary to the terminal device. The chip systemmay include a chip, or may include a chip and another discretecomponent.

In addition, this application further provides a chip system. The chipsystem includes a processor, configured to support a network device inimplementing a function in the foregoing method for sending a referencesignal, for example, sending or processing data and/or information inthe foregoing method. In a possible design, the chip system furtherincludes a memory. The memory is configured to store a programinstruction and data necessary to the network device. The chip systemmay include a chip, or may include a chip and another discretecomponent.

In the foregoing embodiments, the processor may be a central processingunit (CPU), a microprocessor, an application-specific integrated circuit(ASIC), one or more integrated circuits configured to control programexecution in the solutions of this application, or the like. Forexample, the processor may include a digital signal processor device, amicroprocessor device, an analog-to-digital converter, adigital-to-analog converter, and the like. The processor may allocate,based on respective functions of these devices, functions of controllinga mobile device and processing a signal to these devices. In addition,the processor may include a function of operating one or more softwareprograms, and the software program may be stored in the memory.

The function of the processor may be implemented by hardware, or may beimplemented by hardware executing corresponding software. The hardwareor software includes one or more modules corresponding to the foregoingfunction.

The memory may be a read-only memory (ROM) or a static storage device ofanother type that can store static information and an instruction; arandom access memory (RAM) or a dynamic storage device of another typethat can store information and an instruction; or an electricallyerasable programmable read-only memory (EEPROM), a compact discread-only memory (CD-ROM) or another compact-disc storage, an opticaldisc (including compressed disc, laser disk, optical disc, digitalgeneral optical disc, Blu-ray disc, or the like) storage, a magneticdisk storage medium or another magnetic storage device, or any othermedia that can be used to carry or store expected program code in astructural form of an instruction or data and can be accessed by acomputer, but is not limited thereto.

Optionally, the memory and the processor may be physically independentunits, or the memory may be integrated with the processor.

A person of ordinary skill in the art may be aware that, in combinationwith the examples described in the embodiments disclosed in thisspecification, units and algorithm steps can be implemented byelectronic hardware or a combination of computer software and electronichardware. Whether the functions are performed by hardware or softwaredepends on particular applications and design constraint conditions ofthe technical solutions. A person skilled in the art may use differentmethods to implement the described functions for each particularapplication, but it should not be considered that the implementationgoes beyond the scope of this application.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, for a detailed workingprocess of the foregoing system, apparatus, and unit, refer to acorresponding process in the foregoing method embodiment, and detailsare not described herein again.

In the several embodiments provided in this application, it should beunderstood that the disclosed system, apparatus, and method may beimplemented in other manners. For example, the described apparatusembodiment is merely an example. For example, the unit division ismerely logical function division and may be other division in actualimplementation. For example, a plurality of units or components may becombined or integrated into another system, or some features may beignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communication connections may beimplemented by using some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beimplemented in electronic, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected based on actualneeds to achieve the objectives of the technical solutions of theembodiments.

In addition, functional units in the embodiments of this application maybe integrated into one processing unit, or each of the units may existalone physically, or two or more units are integrated into one unit.

With reference to the foregoing description, a person skilled in the artcan be aware that the methods in embodiments of this specification canbe implemented by hardware (for example, a logical circuit), software,or a combination of hardware and software. Whether the methods areperformed by hardware or software depends on particular applications anddesign constraint conditions of the technical solutions. A personskilled in the art may use different methods to implement the describedfunctions for each particular application, but it should not beconsidered that the implementation goes beyond the scope of thisapplication.

When the foregoing functions are implemented in the form of software andsold or used as an independent product, the functions may be stored in acomputer-readable storage medium. In this case, the technical solutionsof this application essentially, or the part contributing to the priorart, or some of the technical solutions may be implemented in a form ofa software product. The computer software product is stored in a storagemedium, and includes several instructions for instructing a computerdevice (which may be a personal computer, a server, a network device, orthe like) to perform all or some of the steps of the methods describedin the embodiments of this application. The foregoing storage mediumincludes any medium that can store program code, such as a USB flashdrive, a removable hard disk, a read-only memory (ROM), a random accessmemory (RAM), a magnetic disk, or an optical disc.

The foregoing descriptions are merely specific implementations of thisapplication, but are not intended to limit the protection scope of thisapplication. Any variation or replacement readily figured out by aperson skilled in the art within the technical scope disclosed in thisapplication shall fall within the protection scope of this application.Therefore, the protection scope of this application shall be subject tothe protection scope of the claims.

What is claimed is:
 1. A method for sending a sounding reference signal(SRS), comprising: receiving, by a terminal device, a firstconfiguration information of an SRS resource of a first slot from anetwork device, wherein the first configuration information comprises arepetition factor L_(r) of the SRS resource, and the first configurationinformation indicates the SRS resource consists of four OFDM symbols;determining, by the terminal device based on n_(SRS), two frequencydomain resources to which the SRS resource is mapped in the first slot;and determining different values of n_(SRS) are associated withdifferent frequency domain resources of the four OFDM symbols, whereinthe n_(SRS) is a count of frequency positions within the SRS resourcethat satisfies:n _(SRS) =└l′/L _(r)┘, where l′ represents a difference between a symbolnumber of the four OFDM symbols in the first slot and a starting symbolnumber of the SRS resource in the first slot, l′=0, 1, 2, or 3, andL_(r)=2; and sending, by the terminal device, an SRS to the networkdevice on the determined two frequency domain resources.
 2. The methodaccording to claim 1, wherein the first configuration informationfurther comprises the starting symbol number of the SRS resource in thefirst slot.
 3. The method according to claim 1, wherein the SRS resourceis configured as aperiodic.
 4. A communication device, comprising: atransceiver, configured to receive first configuration information of asounding reference signal (SRS) resource of a first slot from a networkdevice, wherein the first configuration information comprises arepetition factor L_(r) of the SRS resource, and the first configurationinformation indicates the SRS resource consists of four OFDM symbols;and a processor, configured to determine, based on n_(SRS), twofrequency domain resources to which the SRS resource is mapped in thefirst slot; and determining different values of n_(SRS)are associatedwith different frequency domain resources of the four OFDM symbols,wherein the n_(SRS)is a count of frequency positions within the SRSresource that satisfies:n _(SRS) =└l′/L _(r)┘, where l′ represents a difference between a symbolnumber of the four OFDM symbols in the first slot and a starting symbolnumber of the SRS resource in the first slot, l′=0, 1, 2, or 3, andL_(r)=2; wherein the transceiver is further configured to send, by theterminal device, an SRS to the network device on the determined twofrequency domain resources.
 5. The method according to claim 4, whereinthe first configuration information further comprises the startingsymbol number of the SRS resource in the first slot.
 6. The methodaccording to claim 4, wherein the SRS resource is configured asaperiodic.
 7. A communication device, comprising: a storage mediumincluding executable instructions; and a processor; wherein theexecutable instructions, when executed by the processor, cause thecommunication device to: receive first configuration information of asounding reference signal (SRS) resource of a first slot from a networkdevice, wherein the first configuration information comprises arepetition factor L_(r) of the SRS resource, and the first configurationinformation indicates the SRS resource consists of four OFDM symbols;determine, based on n_(SRS), two frequency domain resources to which theSRS resource is mapped in the first slot; and determine different valuesof n_(SRS) are associated with different frequency domain resources ofthe four OFDM symbols, wherein the n_(SRS)is a count of frequencypositions within the SRS resource that satisfies:n_(SRS) =└l′/L _(r)┘, where l′ represent a difference between a symbolnumber of the four OFDM symbols in the first slot and a starting symbolnumber of the SRS resource in the first slot, l′=0, 1, 2, or 3, andL_(r)=2; and send an SRS to the network device on the determined twofrequency domain resources.
 8. The method according to claim 7, whereinthe first configuration information further comprises the startingsymbol number of the SRS resource in the first slot.
 9. The methodaccording to claim 7, wherein the SRS resource is configured asaperiodic.
 10. A computer-readable storage medium, configured to store acomputer program, wherein the computer program is used to execute aninstruction of the method according to claim
 1. 11. A communicationsystem, comprising a user equipment and a base station, wherein the userequipment is configured to: receive, by a terminal device, a firstconfiguration information of a sounding reference signal (SRS) resourceof a first slot from a network device, wherein the first configurationinformation comprises a repetition factor L_(r) of the SRS resource, andthe first configuration information indicates the SRS resource consistsof four OFDM symbols; determine, by the terminal device based onn_(SRS), two frequency domain resources to which the SRS resource ismapped in the first slot; and determine different values of n_(SRS) areassociated with different frequency domain resources of the four OFDMsymbols, wherein the n_(SRS) is a count of frequency positions withinthe SRS resource that satisfies:n _(SRS) =└l′/L _(r)┘, where l′ represent a difference between a symbolnumber of the four OFDM symbols in the first slot and a starting symbolnumber of the SRS resource in the first slot, l′=0, 1, 2, or 3, andL_(r)=2; and sending, by the terminal device, an SRS to the networkdevice on the determined two frequency domain resources.
 12. The systemaccording to claim 11, wherein the first configuration informationfurther comprises the starting symbol number of the SRS resource in thefirst slot.
 13. The system according to claim 11, wherein the SRSresource is configured as aperiodic.